Citazione Stile APA (7a Edizione)

Weber, W. A., & Wittmann, R. C. (2012). Colorado flora: A field guide to the vascular plants (4th ed.). University Press of Colorado.

Citazione stile Chigago Style (17a edizione)

Weber, William A., e Ronald C. Wittmann. Colorado Flora: A Field Guide to the Vascular Plants. 4th ed. Boulder, Colo.: University Press of Colorado, 2012.

Citatione MLA (9a ed.)

Weber, William A., e Ronald C. Wittmann. Colorado Flora: A Field Guide to the Vascular Plants. 4th ed. University Press of Colorado, 2012.