Ribeiro, Luiz Alberto Oliveira, et al. “Chronic Copper Poisoning in Sheep Grazed under Grape Orchard Fertilise With Poultry Litter”. Brazilian Journal of Veterinary Research and Animal Science, vol. 44, no. 3, June 2007, pp. 208-11, https://doi.org/10.11606/issn.1678-4456.bjvras.2007.26640.