Não informado. (1968). Abstracts of bulgarian scientific medical literature. Ministry of Public Health, Centre for Scientific Medical Information.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Não informado. Abstracts of Bulgarian Scientific Medical Literature. Sofia: Ministry of Public Health, Centre for Scientific Medical Information, 1968.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Não informado. Abstracts of Bulgarian Scientific Medical Literature. Ministry of Public Health, Centre for Scientific Medical Information, 1968.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.