Immunization of pregnant cows with (coligen) to prevent colibacillosis in calves. Iraqi J. Vet. Med. [Internet]. 1986 Dec. 28 [cited 2024 Dec. 21];10(1):27-45. Available from: https://jcovm.uobaghdad.edu.iq/index.php/Iraqijvm/article/view/1844