APA (7th ed.) Citation

GALLUP, H. F. (1969). An invitation to modern pdychology.

Chicago Style (17th ed.) Citation

GALLUP, Howard F. An Invitation to Modern Pdychology. 1969.

MLA (8th ed.) Citation

GALLUP, Howard F. An Invitation to Modern Pdychology. 1969.

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