Pinto, Marcelo Souza, et al. “Effect of Green Propolis Extracts on Patogenic Bacteria Isolated from Milk of Cows With Mastitis”. Brazilian Journal of Veterinary Research and Animal Science, vol. 38, no. 6, Jan. 2001, pp. 278-83, https://doi.org/10.1590/S1413-95962001000600006.