“Immunization of Pregnant Cows With (coligen) to Prevent Colibacillosis in Calves”. The Iraqi Journal of Veterinary Medicine 10, no. 1 (December 28, 1986): 27–45. Accessed July 22, 2024. https://jcovm.uobaghdad.edu.iq/index.php/Iraqijvm/article/view/1844.