PROSTAGLANDIN F2α AND LUTEAL REGRESSION IN THE EWE : COMPARISON WITH 16 ARYLOXYPROSTAGLANDIN (I. C. I. 80, 996) D. T. BAIRD and R. J. SCARAMUZZI Ann. Biol. anim. Bioch. Biophys., 15 2 (1975) 161-174 DOI: 10.1051/rnd:19750203