APA (7th ed.) Citation

Projected Learning Programs, Hungerford, H. R., & Tomera, A. N. (1981). Desert biome. Projected Learning Programs.

Chicago Style (17th ed.) Citation

Projected Learning Programs, Harold R. Hungerford, and Audrey N. Tomera. Desert Biome. Reno, Nev.: Projected Learning Programs, 1981.

MLA (9th ed.) Citation

Projected Learning Programs, et al. Desert Biome. Projected Learning Programs, 1981.