APA

Clausen J., Keck D. D. & Hiesey W. M. (1940). Effect of varied environments on Western North American plants. Washington, D.C: Carnegie Inst.

Chicago

Clausen Jens, Keck David D and Hiesey William McKinley. 1940. Effect of varied environments on Western North American plants. Washington, D.C: Carnegie Inst.

Harvard

Clausen J., Keck D. D. and Hiesey W. M. (1940). Effect of varied environments on Western North American plants. Washington, D.C: Carnegie Inst.

MLA

Clausen Jens, Keck David D and Hiesey William McKinley. Effect of varied environments on Western North American plants. Washington, D.C: Carnegie Inst. 1940.