TWIST, C. Encyclopedia of science: The enviorement ecology, pollution, and agriculture. Volume VII. Macmillan Publishing Company.
Chicago-referens (17:e uppl.)TWIST, Clint. Encyclopedia of Science: The Enviorement Ecology, Pollution, and Agriculture. Volume VII. Macmillan Publishing Company.
MLA-referens (8:e uppl.)TWIST, Clint. Encyclopedia of Science: The Enviorement Ecology, Pollution, and Agriculture. Volume VII. Macmillan Publishing Company.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.