### Pliska Studia Mathematica Bulgarica

**Volume 3, 1981**

EDITOR: R. Denchev
Sofia, 1981

#### C O N T E N T S

**Baynov, D., Milusheva, S. **A substantiation of a averaging method for a class of integro- differential equations of standard form with impulses. (Russian) (pp. 3-19)
**Vainikko, G., Kazakova, N. **On the convergence of the method of finite differences in the case of the determination of periodic solutions for equations of the neutral type. (Russian) (pp. 20-27)
**Tabov, J. **On hyperbolic Pfaffian systems. (Russian) (pp. 28-46)
**Popivanov, P. **Some classes of differential operators with multiple characteristics, which have no solutions. (Russian) (pp. 47-60)
**Yordanov, I. **Regulaires conditions of the solution of a problem non-coercif. (French) (pp. 61-66)
**Georgiev, N. **Investigation of a nonlinear differential system of order. (English) (pp. 67-74)
**Manolov, S. **On the realization of an algorithm for the construction of periodic solutions of autonomous systems of a certain class. (Russian) (pp. 75-87)
**Popivanov, N. **Boundary value problems for hyperbolic-parabolic equations in multidimensional domains. (Russian) (pp. 88-119)

Creator: Laboratory DSCH,
IS Department, 20.12.2011

Available online since: 20.04.2012