Cita APA (7a ed.)

Bobev, P., Brückner, W., & Stoilov, S. (1977). Kaliakra. Sofia-Press.

Cita Chicago Style (17a ed.)

Bobev, Peter, Willi Brückner, y Stoimen Stoilov. Kaliakra. Sofia: Sofia-Press, 1977.

Cita MLA (8a ed.)

Bobev, Peter, et al. Kaliakra. Sofia-Press, 1977.