APA (7th ed.) Citation

Shepard, K., Schmoll, B., Jensen, G., Hack, L., & Gwyer, J. (1991). A model for multiple approaches to clinical research.

Chicago Style (17th ed.) Citation

Shepard, K., B. Schmoll, G. Jensen, L. Hack, and J. Gwyer. A Model for Multiple Approaches to Clinical Research. 1991.

MLA (9th ed.) Citation

Shepard, K., et al. A Model for Multiple Approaches to Clinical Research. 1991.