Martinez J, Thibier M
Vet Rec. 1984 Jul 21;115(3):57-9. doi: 10.1136/vr.115.3.57.
A single injection of prostaglandin F2 alpha or fenprostalene administered during the luteal phase of the oestrous cycle to either post partum or post insemination anoestrous cows resulted in a similar level of efficacy as judged by breeding efficiency.