APA (7th ed.) Citation

Rose, J. N., & Purpus, K. A. (1910). Three new species of Echeveria from southern Mexico. Government Printing Office.

Chicago Style (17th ed.) Citation

Rose, J. N., and Karl Albert Purpus. Three New Species of Echeveria from Southern Mexico. Washington: Government Printing Office, 1910.

MLA (9th ed.) Citation

Rose, J. N., and Karl Albert Purpus. Three New Species of Echeveria from Southern Mexico. Government Printing Office, 1910.