Widayati, D. , Junaidi, A. , Suharto, K. , Oktaviani, A. , Wahyuningsih, W.. "Reproduction Performance of Etawah Cross Bred Goats in Estrus Synchronization by Controlled Internal Drug Release Implant and Pgf2α Continued by Artificial Insemination". World Academy of Science, Engineering and Technology, Open Science Index 41, International Journal of Animal and Veterinary Sciences, (2010), 4(5), 393 - 395.