APA (7th ed.) Citation

Gentry, J. L. (1976). A revision of the genus Hackelia (Boraginaceae) in North America, north of Mexico ([Sonderdr.].). New York Botanical Garden.

Chicago Style (17th ed.) Citation

Gentry, Johnnie L. A Revision of the Genus Hackelia (Boraginaceae) in North America, North of Mexico. [Sonderdr.]. Bronx, N.Y: New York Botanical Garden, 1976.

MLA (9th ed.) Citation

Gentry, Johnnie L. A Revision of the Genus Hackelia (Boraginaceae) in North America, North of Mexico. [Sonderdr.]. New York Botanical Garden, 1976.