Bobev, P., Brückner, W., & Stoilov, S. (1977). Kaliakra. Sofia-Press.
Lua i Stíl Chicago (17ú heag.)Bobev, Peter, Willi Brückner, agus Stoimen Stoilov. Kaliakra. Sofia: Sofia-Press, 1977.
Lua MLA (8ú heag.)Bobev, Peter, et al. Kaliakra. Sofia-Press, 1977.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.