APA

Greenberg E. R., Baron J. A., Stevens M. M., Stukel T. A., Mandel J. S., Spencer S. K., Elias P. M., Lowe N., Nierenberg D. N. & Bayrd G. (19890829). The Skin Cancer Prevention Study: design of a clinical trial of beta-carotene among persons at high risk for nonmelanoma skin cancer. : Controlled clinical trials.

Chicago

Greenberg E R, Baron J A, Stevens M M, Stukel T A, Mandel J S, Spencer S K, Elias P M, Lowe N, Nierenberg D N and Bayrd G. 19890829. The Skin Cancer Prevention Study: design of a clinical trial of beta-carotene among persons at high risk for nonmelanoma skin cancer. : Controlled clinical trials.

Harvard

Greenberg E. R., Baron J. A., Stevens M. M., Stukel T. A., Mandel J. S., Spencer S. K., Elias P. M., Lowe N., Nierenberg D. N. and Bayrd G. (19890829). The Skin Cancer Prevention Study: design of a clinical trial of beta-carotene among persons at high risk for nonmelanoma skin cancer. : Controlled clinical trials.

MLA

Greenberg E R, Baron J A, Stevens M M, Stukel T A, Mandel J S, Spencer S K, Elias P M, Lowe N, Nierenberg D N and Bayrd G. The Skin Cancer Prevention Study: design of a clinical trial of beta-carotene among persons at high risk for nonmelanoma skin cancer. : Controlled clinical trials. 19890829.