Ott, R. S., Bretzlaff, K. N., & Cmarik, G. F. (1983). Field study of the effects of zeranol, implanted at the time of breeding, on weight gain and pregnancy rate of beef heifers. The Bovine Practitioner, 1983(18), 104–106. https://doi.org/10.21423/bovine-vol1983no18p104-106