Cita APA (7a ed.)

Michailov, D., Marinov, D., Smolenov, P., Müller, B., & Papasova, K. (1980). Bulgarien kleiner Reiseführer (o.A.). Sofia-Press.

Cita Chicago Style (17a ed.)

Michailov, Dimiter, Dimo Marinov, Pantscho Smolenov, Barbara Müller, y Käthe Papasova. Bulgarien Kleiner Reiseführer. o.A. Sofia: Sofia-Press, 1980.

Cita MLA (8a ed.)

Michailov, Dimiter, et al. Bulgarien Kleiner Reiseführer. o.A. Sofia-Press, 1980.