APA (7th ed.) Citation

Freedman, P. (1949). The principles of scientific research / by P. Freedman. Macdonald.

Chicago Style (17th ed.) Citation

Freedman, P. The Principles of Scientific Research / by P. Freedman. Macdonald, 1949.

MLA (9th ed.) Citation

Freedman, P. The Principles of Scientific Research / by P. Freedman. Macdonald, 1949.

Warning: These citations may not always be 100% accurate.