APA (7th ed.) Citation

Gregor, H. F. (1970). Geography of agriculture: Themes in research. Prentice-Hall.

Chicago Style (17th ed.) Citation

Gregor, Howard F. Geography of Agriculture: Themes in Research. Englewood Cliffs, N.J.: Prentice-Hall, 1970.

MLA (9th ed.) Citation

Gregor, Howard F. Geography of Agriculture: Themes in Research. Prentice-Hall, 1970.