APA (7th ed.) Citation

Duellman, W. E., & Trueb, L. (2011). A Synopsis of Neotropical Hylid Frogs, Genus Osteocephalus. Project Gutenberg.

Chicago Style (17th ed.) Citation

Duellman, William Edward, and Linda Trueb. A Synopsis of Neotropical Hylid Frogs, Genus Osteocephalus. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Duellman, William Edward, and Linda Trueb. A Synopsis of Neotropical Hylid Frogs, Genus Osteocephalus. Project Gutenberg, 2011.

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