APA (7th ed.) Citation

Cobb, E., Cobb, B. B., Cram, A. G., & Levis, W. (2008). Clematis. Project Gutenberg.

Chicago Style (17th ed.) Citation

Cobb, Ernest, Bertha B. Cobb, Allan G. Cram, and Willis Levis. Clematis. Project Gutenberg, 2008.

MLA (9th ed.) Citation

Cobb, Ernest, et al. Clematis. Project Gutenberg, 2008.

Warning: These citations may not always be 100% accurate.