The group structure of Hecke groups H $(lambda_q)$

İ. N. CANGÜL

($sigma$, $tau$)-Lie ideals in prime rings with derivation

Muharrem SOYTÜRK

Star topological groupoids

O. MUCUK

A note on double sequences of fuzzy numbers

E. SAVAŞ

Relations between classes of Dragilev spaces $(f_1)_{sigma}$ and $(f_2)_{sigma}$ sigma for arbitrary function $f^{-1}_1 circ f_2$.

V. KASHIRIN, A. VAKULENKO

Extensions of Caristi-Kirk's theorem

M. O. DIALLO, M. OUDADESS

$T_2$-objects in categories of filter and local filter convergence spaces

M. BARAN

Absolutely representing systems and convolution operators in the complex domain

Yu F. KOROBEINIK

Normal boundary value problems for differential equations of higher order

F. G. MAKSUDOV, Z. I. ISMAILOV

Rings in which strongly prime right ideals are finitely generated

Arif KAYA