APA (7th ed.) Citation

Hehr, T. J. H., Campbell, J. K., & Koeing, K. J. (1988). Content validation of Texas State-Adopted life, earth, physical, and biological science textbooks.

Chicago Style (17th ed.) Citation

Hehr, Terry Jane Hanger, Jack K. Campbell, and Karl J. Koeing. Content Validation of Texas State-Adopted Life, Earth, Physical, and Biological Science Textbooks. 1988.

MLA (9th ed.) Citation

Hehr, Terry Jane Hanger, et al. Content Validation of Texas State-Adopted Life, Earth, Physical, and Biological Science Textbooks. 1988.