APA (7th ed.) Citation

Penhallow, D. P. (1907). A manual of the North American gymnosperms: Exclusive of the cycadales but together with certain exotic species. Ginn.

Chicago Style (17th ed.) Citation

Penhallow, D. P. A Manual of the North American Gymnosperms: Exclusive of the Cycadales but Together with Certain Exotic Species. Boston: Ginn, 1907.

MLA (8th ed.) Citation

Penhallow, D. P. A Manual of the North American Gymnosperms: Exclusive of the Cycadales but Together with Certain Exotic Species. Ginn, 1907.