APA

Frank P. G., . (1961). The validation of scientific theories. New York: Collier Books.

Chicago

Frank Philipp G, . 1961. The validation of scientific theories. New York: Collier Books.

Harvard

Frank P. G., . (1961). The validation of scientific theories. New York: Collier Books.

MLA

Frank Philipp G, . The validation of scientific theories. New York: Collier Books. 1961.