Thornquist MD, Patrick DL, Omenn GS. Participation and adherence among older men and women recruited to the Beta-Carotene and Retinol Efficacy trial (CARET). Gerontologist. 1991 Oct;31(5):593-7.
Thornquist MD, Patrick DL, Omenn GS. Participation and adherence among older men and women recruited to the Beta-Carotene and Retinol Efficacy trial (CARET). Gerontologist. 1991 Oct;31(5):593-7.