Rayan, M. O., A. E.- din Zain El-abedeen, and M. R. Abd Ellah. “Some Metabolic Parameters During Transition Period in Dairy Cows With and Without Retained Fetal Membranes”. Journal of Advanced Veterinary Research, vol. 9, no. 2, Mar. 2019, pp. 45-48, https://advetresearch.com/index.php/AVR/article/view/346.