CONTRERAS, P.A., WITTWER, F., RUIZ, V., ROBLES, A. and BRÖHMWALD, H. 1999. Blood values of thyroxine and triiodothyronine in grazing Friesian cows. Archivos de Medicina Veterinaria. 31, 2 (Dec. 1999), 205–210. DOI:https://doi.org/10.4067/S0301-732X1999000200007.