Serdica Bulgariacae mathematicae publicationes

Volume 15, 1989

Number 1

• Fedeli, A. A-compact spaces. (pp. 3-11)
• Konopka, C. On extrinsic spheres in Sasakian manifolds. (pp. 12-15)
• Kyurkchiev, Nikolaj V. On a class of two-sided iterative methods for solving nonlinear equations. (in Russian) (pp. 16-18)
• Wegner, B. Über das kritische Verhalten zylindrischer Abstandsfunktionen auf Untermannigfaltigkeiten euklidischer Räume. (On the critical behavior of cylindrical distance functions on submanifolds of euclidean spaces.) (in German) (pp. 19-27)
• Rachev, S. T., A. Yu. Yakovlev, N. O. Kadyrova. A concept of D-stochastic ordering and its application to the competing risks model. (pp. 28-31)
• Todorinov, S.A., N. L. Petrova. Directionally non-orderable groups. (pp. 32-33)
• Lucchetti, R. Stability in optimization. (pp. 34-48)
• Stanilov, G. Characteristic curvatures in the almost Hermitian geometry. (pp. 49-52)
• Popivanov, P. R., N. D. Kutev. On the tangential oblique derivative problem for a class of elliptic second order quasilinear differential equations. (pp. 53-62)
• Borubaev, A. A. Completion of uniform spaces and extensions of topological spaces. (in Russian) (pp. 63-73)
• Kadomtsev, S. B. On two-dimensional surfaces with constant extrinsic geometry. (in Russian) (pp. 74-77)
• Kassabov, O. T. Diffeomorphisms of pseudo-Riemannian manifolds and the values of the curvature tensor on degenerate planes. (pp. 78-86)

Number 2

• Vandev, D., N. Trendafilov. A type of stable stochastic processes using Levy-Khintchine formulae. (pp. 87-90)
• Ignatov, Z. G., V. K. Kaishev. A probabilistic interpretation of multivariate B-splines and some applications. (pp. 91-99)
• Gajdov, S. D. Objection and counter-objection equilibria in many-player stochastic differential games. (pp. 100-107)
• Drenska, Natalia T. Numerical method for solving an elliptic equation of fourth order. (pp. 108-113)
• Dodunekova, R. Detecting the signal appearing time. (pp. 114-118)
• Sipacheva, O. V. Zero-dimensionality and completeness in free topological groups. I. (in Russian) (pp. 119-140)
• Sipacheva, O. V. Zero-dimensionality and completeness in free topological groups. II. (in Russian) (pp. 141-154)
• Stankov, D. K. On an algebra of functions on the boundary of the generalized unit sphere. (in Russian) (pp. 155-159)
• Skordev, G. S. The multiplicativity property of the fixed point index for multivalued maps. (pp. 160-170)

Number 3

• Tarkhanov, N. N., D. M. Shojkhet. A remark on the probability of degeneration of a multidimensional branching Galton-Watson process. (pp. 171-173)
• Szász, F. A. On Jacobson radical rings. (pp. 174-175)
• Janous, W. A minimum problem for a class of polynomials. (pp. 176-178)
• Rodríguez, J. Operational calculus for the generalized Bessel operator. (pp. 179-186)
• Boju, V., L. Funar. Courbure et changements conformes de metrique. (Curvature and conformal change of the métric). (in French) (pp. 187-191)
• Popov, V. An easily computed upper bound for the condition number of a matrix. (pp. 192-196)
• Trencevski, K. A formula for the k-th covariant derivative. (pp. 197-202)
• Dia, G. Loi limite du regressogramme pour un processus ponctuel. (Limit law of the regressogram for a point process). (in French) (pp. 203-209)
• Koneva, N. P. Congruences W in a biaxial space of hyperbolic type. (in Russian) (pp. 210-216)
• Al-Bassam, M.A., S. L. Kalla. On orthogonal polynomials associated with differential equations of Laguerre type. (pp. 217-222)
• Satimov, N., A.Z. Fazylov. Avoiding collisions in linear systems with integral constraints. (in Russian) (pp. 223-231)
• Owa, S., V. Micic, M. Obradovic. Note on certain subclasses of univalent functions with quasiconformal extension. (pp. 232-238)
• Chakalov, V. L. On a generalization of the Markov-Krein (f,y)-problem. (in Russian) (pp. 239-251)
• Cristev, D. I. On some properties of solutions of semilinear elliptic differential equations and inequalities. (in Russian) (pp. 252-258)
• Pavlov, E. Conformal-holomorphic invariants. (pp. 259-265)
• Aleksiev, V. On a class of almost contact metric manifolds conformally related to the Sasakian manifolds. (pp. 266-270)
• Tabov, J. B. On the local solvability of hyperbolic overdetermined systems of partial differential equations. (pp. 271-274)

Number 4

• Bovdi, A. A., K. Kh. Kolikov. Lie nilpotency and ideals of crossed products. (in Russian) (pp. 275-286)
• Papageorgiou, N. S. On the existence of f-minimal viable solutions for a class of differential inclusions. (pp. 287-292)
• Drensky, V. S., T. G. Rashkova. Varieties of metabelian Jordan algebras. (pp. 293-301)
• Kyurkchiev, N. V., A. S. Andreev. A two-sided method for simultaneous computation of multiple zeros of a polynomial equation. (in Russian) (pp. 302-304)
• Cristev, D. I. A theorem of Phragmen-Lindelof type for parabolic equation of second order. (pp. 305-308)
• Genov, G. K., P. N. Siderov. On some properties of the Grigorchuk group and its group algebra over a field of characteristic two. (in Russian) (pp. 309-326)
• Goel, R. M., B. S. Mehrok A coefficient inequality for a sub-class of close-to-convex functions. (pp. 327-335)
• Kryszewski, W., D. Miklaszewski The Nielsen number of set-valued maps. An approximation approach. (pp. 336-344)
• Petkova, S. V. Spaces with Steenrod-Sitnikov torsion homologies. (in Russian) (pp. 345-350)
• Mikhova, V. Canonical connection and the canonical conformal group on a Riemannian almost-product manifold. (pp. 351-358)