Ribeiro Filho, A. de L., A. S. Rodrigues, M. C. C. Lima, P. A. Ferraz, M. V. G. Loiola, and R. F. Bittencourt. “PREGNANCY RATE OF CATTLE EMBRYO RECIPIENT WITH DIFFERENT DEGREES OF DIFFICULTY ON EMBRYO TRANSFER PROCEEDING”. Brazilian Animal Science/ Ciência Animal Brasileira, vol. 12, no. 4, Dec. 2011, pp. 727-32, doi:10.5216/cab.v12i4.12414.