Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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