Bozilova, Elisaveta D B; Filipova, Mariana V F M (1986): Paleoecological environment in northeastern Black Sea area during Neolithic, Eneolithic and Bronze periods. Studia Praehistoria, 8, 160-165
Filipova, Mariana V F M (1985): Plaeoecological investigations of Lake Shabla-Ezeretz in NE Bulgaria. Ecologia Mediterranea, 11(1), 148-158