Perkins, W. H. (1938). Cause and prevention of diseases. Lea & Febiger.
Lua i Stíl Chicago (17ú heag.)Perkins, William Harvey. Cause and Prevention of Diseases. Philadelphia: Lea & Febiger, 1938.
Lua MLA (8ú heag.)Perkins, William Harvey. Cause and Prevention of Diseases. Lea & Febiger, 1938.
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