Preprints Preprints in Bulgarian Papers in Computer-Generated Mathematics Papers in the Journal of Computer-Generated Euclidean Geometry Papers in Algebra and Mathematical Logic Proceedings of the American Mathematical Society published by the American Mathematical Society 1992    The class of all S-pregroups is not finitely axiomatizable, vol.115, no.4, pp.895-897. (Communicated by Warren J. Wong) Journal of Algebra published by Academic Press        1991    The Embedding of Semigroup Amalgams, vol.141, pp.158-161. (Communicated by T. E. Hall) Semigroup Forum published by Springer-Verlag        1993    Free Products with Amalgamation of Semigroups, vol.46, pp.54-61. (Communicated by J. M. Howie) 1994    HNN Extensions of Semigroups, vol.49, pp.83-87. (Communicated by Boris M. Schein) 1999 Deciding Embeddability of Partial Groupoids into Semigroups,vol.58, pp.395-414. (Communicated by G. Lallement) Journal of Symbolic Logic published by the Association for Symbolic Logic 1995    Embeddability and the word problem, vol.60, pp. 1194-1198. Journal of Pure and Applied Algebra Published by Elsevier Science 1998    Free products with amalgamation of monoids,vol.125, pp.129-133. (Communicated by P. Freyd) 1998    The class of all embeddable semigroup amalgams is not finitely axiomatizable, vol.125, pp.135-139. (Communicated by P. Freyd) Communications in Algebra Published by Marcel Dekker 1997    Finite Complete Rewriting Systems for Groups,vol.25, pp.4023-4028. Mathematica Balkanica published by the Bulgarian Academy of Sciences 2001    Finite Complete Rewriting Systems for Semigroups and Groups, vol. 15, pp. 125-138. (Communicated by P. Kenderov) Papers related to the degree Ph.D. in Mathematics University of Sofia, 1985 Proceedings of the Bulgarian Academy of Sciences 1977    Projections des classes n-polaires,vol.30, no.6, pp.801-804. (Communicated by B. Petkantchin) 1979    Precategories quotient, vol.32, no.12, pp.1619-1622. (Communicated by L. Iliev) 1980    Classes polaires quotient, vol.33, no.1, pp.11-14. (Communicated by L. Iliev) 1986    Sur l'existence de structures quotient, vol.40, no.7, pp.17-19 (Communicated by L. Iliev) Serdica. Mathematical Journal published by Institute of Mathematics and Computer Science, Bulgarian Academy of Sciences 1988    Problemes universels relatifs aux classes polaires,vol.14, pp.223-233. 1988    Existence de structures quotient, vol.14, pp.343-349. 1990    Problemes universels relatifs aux classes polaires des relations, vol.16, pp.14-18. Bul. Inst. Politehnic Iasi 1981    Categories de trios et des quatuors,vol.27, no.1-2, p.13 Revue roumaine mathematiques pures et appliquees 1982    Sur les structures algebriques des relations,vol.27, no.1, pp.15-24. Proceedings of the Symposium on n-ary Structures, Skopje, 1982 1982    On the analog of Post theorem for polyadic monoids,pp.171-173.