Não informado. (1972). Annals of the Research Institute of Epidemiology and Microbiology. Ministery of Public Health.
Cita Chicago Style (17a ed.)Não informado. Annals of the Research Institute of Epidemiology and Microbiology. Sofia: Ministery of Public Health, 1972.
Cita MLA (8a ed.)Não informado. Annals of the Research Institute of Epidemiology and Microbiology. Ministery of Public Health, 1972.
Precaución: Estas citas no son 100% exactas.