APA (7th ed.) Citation

Neill, W., & Hepburn, D. (2001). The guide to butterflies of Oregon and Washington. Westcliffe Publishers.

Chicago Style (17th ed.) Citation

Neill, William, and Doug Hepburn. The Guide to Butterflies of Oregon and Washington. Englewood, CO: Westcliffe Publishers, 2001.

MLA (8th ed.) Citation

Neill, William, and Doug Hepburn. The Guide to Butterflies of Oregon and Washington. Westcliffe Publishers, 2001.

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