Não informado. (1957). Abstracts of Bulgarian Scientific Literature. Centre of Scientific Information and Documentation.
Citação do estilo Chicago (17ª ed.)Não informado. Abstracts of Bulgarian Scientific Literature. Sofia: Centre of Scientific Information and Documentation, 1957.
Citação MLA (8ª ed.)Não informado. Abstracts of Bulgarian Scientific Literature. Centre of Scientific Information and Documentation, 1957.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.