Chegini, A., A. A. Shadparvar, N. G. Hossein-Zadeh, and B. Mohammad-Nazari. “Genetic and Environmental Relationships Among Milk Yield, Persistency of Milk Yield, Somatic Cell Count and Calving Interval in Holstein Cows”. Revista Colombiana De Ciencias Pecuarias, vol. 32, no. 2, May 2019, pp. 81-89, doi:10.17533/udea.rccp.v32n2a01.