Não informado. Problems of Infectious and Parasitic Diseases. Medical Academy.
Chicago-viite (17. p.)Não informado. Problems of Infectious and Parasitic Diseases. Sofia: Medical Academy.
MLA-viite (8. p.)Não informado. Problems of Infectious and Parasitic Diseases. Medical Academy.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.