List of  peer-reviewed publications

1)    Baicheva T., Topalova S., Classification of optimal (v, k, 1) binary cyclically permutable constant weight codes with k=5, 6 and 7 and small lengths, Designs Codes and Cryptography 87 (2 – 3)  (2019), 1573-7586.

2)    Topalova S., Zhelezova S., Types of spreads and duality of the parallelisms of PG(3,5) with automorphisms of order 13, Designs, Codes and Cryptography 87 (2 – 3) (2019), 495-507.

3)    Baicheva T., Topalova S., Classification of strongly conflict-avoiding codes, IEEE Communications Letters 22 (12) (2018),  2415-2418.   ثوٍي

4)    Betten A., Topalova S., Zhelezova S., Parallelisms of PG(3, 4) invariant under a Baer involution, Proceedings of the 16th International Workshop on Algebraic and Combinatorial Coding Theory, Svetlogorsk, Russia, 2018, 57-61.  

5)    Baicheva, T., Topalova S., On Tight Optimal Conflict-avoiding Codes for 3, 4, 5 and 6 Active Users, Cybernetics and Information Technologies 18 (5) (2018),  5-11.   

6)    Baicheva T., Topalova S., Classification of optimal conflict-avoiding codes of weights 6 and 7, Electronic Notes in Discrete Mathematics 57 (2017), 9 – 14.

7)    Baicheva T., Topalova S., Optimal conflict-avoiding codes for 3, 4 and 5 active users, Problems of Information Transmission 53 (1) (2017), 42 - 50.

8)    S. Topalova, S. Zhelezova, New parallelisms of PG(3, 4),  Electronic Notes in Discrete Mathematics 57 (2017), 193 - 198.

9)    Topalova S., Zhelezova S., New regular parallelisms of PG(3,5), Journal of Combinatorial Designs 24 (10) (2016), 473 - 482..

10)         Topalova S., On the resolutions of cyclic Steiner triple systems with small parameters, Journal of Algebra Combinatorics Discrete Structures and Applications 3 (3) (2016), 201 - 208.

11)         Topalova S., Conjugates for finding the automorphism group and isomorphism of design resolutions, Serdica Journal of Computing 10 (1) (2016), 79 – 92.

12)         T. Baicheva and S. Topalova, Construction and classification of optimal (v,5,3,1) optical orthogonal codes, International Scientific Journal Science. Business. Society 5 (2016), 7 - 8.

13)         S. Topalova, S. Zhelezova, On point-transitive and transitive deficiency one parallelisms of  PG(3,4), Designs Codes and Cryptography 75(1) (2015), 9-19.

14)         Baicheva T., Topalova S., Maximal (v,4,3,1) optical orthogonal codes for asynchronous transmission. In Proc. Scientitfic Jubilee Conference 25 Years Faculty of Mathematics and Informatics, Veliko Tarnovo, Bulgaria (2015), 80--85.

15)         T. Baicheva, S. Topalova, Classification of maximal optical orthogonal codes of weight 3 and small lengths, Serdica Journal of Computing 9(1) (2015), 83 – 92.

16)         S. Topalova, S. Zhelezova, Doubly resolvable designs with small parameters,  Ars Combinatoria 117 (October) (2014), 289-302.

17)         R. Shaw, S. Topalova, Book spreads in PG (7, 2), Discrete Mathematics 330 (2014), 76-86.

18)         T. Baicheva, S. Topalova,  New perfect difference families, Fourteenth International Workshop on Algebraic and Combinatorial Coding Theory, September 7–13, 2014, Svetlogorsk (Kaliningrad region), Russia, 18–23.

19)         McDonough T.P., Shaw R., Topalova S., Classification of book spreads in PG(5,2),  Note Di Matematica,  33(2) (2013), 43-64.

20)         Topalova S., Zhelezova S., Orthogonal resolutions and latin squares, Serdica Journal of Computing 7(1) (2013), 13 - 24.

21)         Topalova S., Zhelezova S., On transitive parallelisms of PG(3,4), Applicable Algebra in Engineering, Communication and Computing 24 (3-4) (2013), 159 - 164.                                                                   

22)         Baicheva T., Topalova S.,  Optimal (v,5,2,1) optical orthogonal codes of small v, Applicable Algebra in Engineering, Communication and Computing 24 (3-4) (2013), 165 - 177.

23)         S. Topalova, S. Zhelezova, Parallelisms of PG(3,5) with automorphisms of order 13, Proceedings of the Seventh International Workshop on Optimal Codes and Related Topics,  Albena, Bulgaria (2013), 176 – 180.

24)         Baicheva T., Topalova S., Classification results for (v, k, 1) cyclic difference families with small parameters, Mathematics of Distances and Applications, M. Deza, M. Petitjean, K. Markov eds., in International book series: Information Science and Computing, book 25 (2012),  24 – 30.                                  

25)         T. Baicheva,  S. Topalova, Optimal (v, 3, 1) binary cyclically permutable constant weight codes with small v, Proc. of the International Workshop on Algebraic and Combinatorial Coding Theory, Pomorie, Bulgaria, pp. 41 -- 46, 2012.

26)         R. Shaw,  S.Topalova, On the types of book spreads of PG(7,2), Proc. of the International Workshop on Algebraic and Combinatorial Coding Theory, Pomorie, Bulgaria, pp. 293 - 298, 2012.

27)         S. Topalova, S. Zhelezova, Parallelisms of PG(3,4) with automorphisms of order 5, Proc. of the International Workshop on Algebraic and Combinatorial Coding Theory, Pomorie, Bulgaria, pp. 311- 316, 2012.

28)         T. Baicheva, S. Topalova, Classification results for (v, k, 1) cyclic difference families with small parameters, Abstracts of ITHEA International Conference "Mathematics of Distances and Applications" (MDA 2012), p. 12, 2012.

29)         T. Baicheva, S. Topalova, Optimal (v, 4, 2, 1) optical orthogonal codes with small parameters , Journal of Combinatorial Designs 20 (2) (2012),  142-160.

30)         T. Baicheva, S. Topalova, Classification of optimal (v,4,1) binary cyclically permutable constant-weight codes and cyclic 2-(v,4,1) designs with v£76, Problems of Information Transmission 47(3) (2011),  224–231.

31)         T. Baicheva and S. Topalova, Optimal (v, 5, 2, 1) optical orthogonal codes with v≤104,  Proc. of Annual Workshop on Coding Theory and Applications, Gabrovo, Bulgaria (2011), 11-14.

32)         T. Baicheva and S. Topalova, Classification of optical orthogonal codes and spreads by backtrack search on a parallel computer, Proc. of Annual Workshop on Coding Theory and Applications, Gabrovo, Bulgaria (2011), 7-10.

33)         S. Topalova, S. Zhelezova, 2-spreads and transitive and orthogonal 2-parallelisms of PG(5,2), Graphs and Combinatorics,  26(5) (2010), 727 -  735.

34)         T. Baicheva and S. Topalova, An algorithm for classification of optimal optical orthogonal codes , Proc. of Annual Workshop Coding Theory and Applications, Veliko Tarnovo, Bulgaria (2010) 11-14.

35)         T. Baicheva and S. Topalova, Classification of optimal (v,4,1) optical orthogonal codes with v<=76, Proc. of the International Workshop on Algebraic and Combinatorial Coding Theory, Novosibirsk, Russia (2010), 26-30.

36)         S. Topalova, S. Zhelezova,   Parallelisms of PG(3,4) with automorphisms of order 7, Proceedings of the Sixth International Workshop on Optimal Codes and Related Topics,  Varna, June 2009, Bulgaria, 184-188.

37)         Z. Mateva, S. Topalova, Hadamard 2-(63,31,15) designs invariant under the dihedral group of order 10, Discrete Mathematics, Volume 309,  Issue 6 (2009), 1347-1356.

38)         Z. Mateva, S. Topalova, Line spreads of PG(5,2), Journal of Combinatorial Designs 17(1) (2009), 90-102.

39)         S.Topalova, S.Zhelezova, Classification of doubly resolvable designs and orthogonal resolutions,  Enhancing Cryptographic Primitives with Techniques from Error Correcting codes, B.Preneel, S.Dodunekov, V. Rijmen, S. Nikova eds., in NATO Science for Peace and Security Series - D: Information and Communication Security, Volume 23,  IOS Press, Amsterdam (2009), 260 - 264.

40)         S. Topalova, S. Zhelezova,   Sets of mutually orthogonal resolutions of BIBDs, Proceedings of the Eleventh International Workshop on Algebraic and Combinatorial Coding Theory, Pamporovo, Bulgaria (2008), 280-285.

41)         S. Topalova, S. Zhelezova,  Classification of the 2-spreads of PG(5,2), Mathematics and Education in Mathematics (2008), 163-169.

42)         Kaski P., Östergård P., Topalova S., Zlatarski R.,   Steiner Triple Systems of Order 19 and 21 with Subsystems of Order 7, Discrete Mathematics 308 (2008), 2732-2741.

43)         Z. Mateva, S. Topalova, Doubles of Hadamard 2-(19,9,4) Designs with Automorphisms of Order 3, Proceedings of the Fifth International Workshop on Optimal Codes and Related Topics, Balchik, June 2007, Bulgaria, 183-189.

44)         S. Topalova, S. Zhelezova, On an algorithm for a double resolvability test, Proc. Intern. Conference on Theory and Applications of Mathematics and Informatics, Alba Iulia, Romania (2007),  Acta Universitatis Apulensis No 15 (2008), 323-329.

45)         Z. Mateva, S. Topalova, Quasidoubles of Hadamard 2-(15,7,3) Designs with Automorphisms of Order 3, Mathematics and Education in Mathematics (2007), 180-185.

46)         V. Fack, S. Topalova, J. Winne, R. Zlatarski,  Enumeration of the doubles of the projective plane of order 4, Discrete Mathematics 306 (2006) 2141-2151.

47)         Z. Mateva, S. Topalova, Enumeration of 2-(15,7,6) designs with automorphisms of order 7 or 5, Mathematics and Education in Mathematics (2006), 270-274.

48)         S. Topalova, S. Zhelezova, On the structure of doubly resolvable 2-(21,3,1) designs, Proceedings of the Tenth International Workshop on Algebraic and Combinatorial Coding Theory, Zvenigorod, Russia (2006), 263-268.

49)         S. Topalova, S. Zhelezova, On the classification of doubly resolvable designs, Proceedings of the Fourth International Workshop on Optimal Codes and Related Topics, Pamporovo, June 2005, Bulgaria, 265-268.

50)         V. Fack, S. Topalova, J. Winne, Enumeration of the reducible 2-(21,5,2) designs,  Proceedings of the Fourth International Workshop on Optimal Codes and Related Topics , Pamporovo, Bulgaria (2005), 146-151.

51)         V. Fack, S. Topalova, J. Winne, On the enumeration of uniquely reducible double designs, Proceedings of EUROCOMB'2005 (Berlin, Germany), 2005, 129-132.

52)         Topalova S., STS(21) with Automorphisms of order 3 with 3 fixed points and 7 fixed blocks, Mathematica Balkanica  18 (1-2) (2004),  215-220.

53)         Topalova S., Zlatarski R., Construction of doubles of the 2-(21,5,1) design with automorphisms of order 2, Proceedings of the Ninth International Workshop on Algebraic and Combinatorial Coding Theory, Kranevo, Bulgaria (2004), 379-383.

54)         Topalova S., Classification of Hadamard matrices of order 44 with Automorphisms of order 7, Discrete Mathematics 260 (1-3) (2003), 275-283.

55)         Topalova S., Zlatarsky R., On STS(21) of Wilson type, Proceedings of the Eighth International Workshop on Algebraic and Combinatorial Coding Theory, Tsarskoe Selo, Russia (2002), 249 - 252.

56)         Topalova S., Zlatarsky R., Construction of STS(21) of Wilson type with automorphisms of order 2 with 3 fixed ponts, Proceedings of the EWM International Workshop on Groups and Graphs, Varna, Bulgaria (2002), 111 - 114.

57)         Topalova S., Groups of automorphisms and enumeration of combinatorial designs, Proceedings of the EWM International Workshop on Groups and Graphs, Varna, Bulgaria (2002), 105 - 110.

58)         Topalova S., Zlatarsky R., Construction of STS(21) with automorphisms of order 2, Proceedings of the Third International Workshop on Optimal Codes and Related Topics, Sunny Beach, Bulgaria (2001), 147 - 150.

59)         Topalova S., Symmetric 2-(69,17,4) Designs with Automorphisms of order 13, J. Statistical Planning and Inference 95 (2001), 335 - 339.

60)         Solov'eva F., Topalova S., Perfect binary codes and Steiner triple systems with the maximal order of the automorphism group, Diskretnii analis i issledovanie operatsii series 1, vol. 7, N4 (2000), 101-110 (in Russian).

61)         Solov'eva F., Topalova S., On the automorphism group of perfect binary codes and Steiner triple systems, Problems of Information Transmission  36 (4) (2000), 331-335.

62)          Solov’eva F. I., Topalova S. T. On the automorphism groups of perfect binary codes, Proc. Seventh Int. Workshop on Algebraic and Comb. Coding Theory. Bansko, Bulgaria (2000), 283–287.

63)         Topalova S., Hadamard matrices of order 44 with automorphisms of order 7, Proceedings of the Seventh International Workshop on Algebraic and Combinatorial  Coding Theory, Bansko, Bulgaria} (2000), 305-310.

64)         Topalova S., 2-(51,6,2) designs with automorphisms of order 51, Proceedings of the Sixth International Workshop on Algebraic and Combinatorial  Coding Theory, Pskov, Russia (1998), 220-223.

65)         Topalova S., Hadamard 2-(43,21,10) designs with automorphisms of order 21 and binary self-dual codes of lengths 86 and 88, Proceedings of the Second International Workshop on Optimal Codes and Related Topics, Sozopol, Bulgaria (1998), 193-197.

66)         Topalova S., Designs from tactical configurations, Mathematics and Education in Mathematics (1998), 135-138.

67)         Topalova S., Construction and study of combinatorial designs with certain automorphisms, Ph. D. Thesis, Sofia (1998) (in Bulgarian).

68)         Topalova S., Enumeration of 2-(21,5,2) designs with automorphisms of an odd prime order, Discretnyi Analis i Issledovanie operatsii (In Russian) series 1, vol.5, N1 (1998), 64-81.

69)         Kapralov S.N., Topalova S., Enumeration of 2-(21,6,3) Designs with Automorphisms of Order 7 or 5, Ars Combinatoria 48 (1998), 135-146.

70)         Landjev I., Topalova S., New Symmetric (61,16,4) designs invariant under the dihedral group of order 10, Serdika Mathematical Journal 24 (2) (1998), 179-186.

71)         Topalova S., Enumeration of 2-(25,5,2) Designs with an automorphism of order 5, Journal of  Combinatorics, Information and System Sciences 22 (3-4) (1997), 161-176.

72)         Topalova S., On the order of the automorphism group of 2-(40,10,3) designs, Mathematics and Education in Mathematics (1996), 161-166.

73)         Topalova S., Enumeration of 2-(25,5,2) Designs with an Automorphism of order 5 with 5 fixed points and 10 fixed blocks,    Mathematics and Education in Mathematics  (1997), 198-201.

74)         Topalova S., Enumeration of 2-(25,5,2) Designs with automorphisms of order 5 without fixed points and with 5 or 10 fixed blocks, Proceedings of the Fifth International Workshop on Algebraic and Combinatorial Coding Theory, Sozopol, Bulgaria  (1996), 288-294.

75)         Topalova S., Enumeration of 2-(21,5,2) designs with an automorphism of order 5, Mathematics and Education in Mathematics  (1995), 241-253.

76)         Topalova S., Enumeration of 2-(21,5,2) designs with an automorphism of order 7, Proceedings of the Fourth International Workshop on Algebraic and Combinatorial  Coding Theory, Novgorod, Russia  (1994), 187-189.

77)         Baicheva Ts., Bogdanova G., Ilieva S., Topalova S., Object-oriented C++ library for computations in and over finite fields of characteristic 2, Mathematics and Education in Mathematics (1994), 227-230.

78)         Kapralov S.N., Topalova S., On the Steiner Triple Systems of order 21 with automorphisms of order 3, Proceedings of the Third International Workshop on Algebraic and Combinatorial Coding Theory, V.Voda, Bulgaria (1992), 105-108.

79)         Manev N., Topalova S., A software system for testing Reed-Solomon codes in different channels,    Mathematics and Education in Mathematics (1992) (in Bulgarian), 304-306.

80)         Baicheva T., Topalova S., Bogdanova G., Ilieva S., Software implementation of spectral methods for coding and decoding of BCH codes,  Mathematics and Education in Mathematics (1992) (in Bulgarian), 291-294.

 

Ph. D. Thesis

                   Topalova S., Construction and study of combinatorial designs with certain automorphisms, Ph. D. Thesis, Sofia (1998) (in Bulgarian).