APA

De Kruif P., . (1938). The fight for life. New York: Harcourt, Brace and company.

Chicago

De Kruif Paul, . 1938. The fight for life. New York: Harcourt, Brace and company.

Harvard

De Kruif P., . (1938). The fight for life. New York: Harcourt, Brace and company.

MLA

De Kruif Paul, . The fight for life. New York: Harcourt, Brace and company. 1938.