“Dispertion Equation of Wave Regime for Film Frainage With Elastic Properties of Interface Boundaries”. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics 86, no. 2 (December 12, 1994): 169–179. Accessed January 11, 2026. https://annual.uni-sofia.bg/index.php/fmi/article/view/511.