Zschöck, Michael, Amr El-Sayed, Nawara Eissa, Christoph Lämmler, and Hugo Castañeda Vazquez. 2013. “Penicillin G and Oxacillin Resistance in Staphylococcus Aureus Strains Isolated from Bovine Subclinical Mastitis”. Veterinaria México OA 42 (3). https://veterinariamexico.fmvz.unam.mx/index.php/vet/article/view/287.