Petar Stoyanov

Kalina Milkova

Marin Bachvarov

Dimitrina Mihova

Atanas Dermendzhiev

Akihiro Kinda

Boyka Bachvarova

Hristo Ganev

Klaus Franz

Milena Guest

Lyuben Hristov

Rumen Yankov

Toni Traykov

Boris Kazakov

Instructions for the authors: