Wood, T.; Weckman, T. J.; Henry, P. A.; Chang, S.-L.; Blake, J. W.; Tobin, T. (). „Equine urine pH: Normal population distributions and methods of acidification”. Equine Veterinary Journal. 22 (2): 118–21. doi:10.1111/j.2042-3306.1990.tb04222.x. PMID2318175.
Wood, T.; Weckman, T. J.; Henry, P. A.; Chang, S.-L.; Blake, J. W.; Tobin, T. (). „Equine urine pH: Normal population distributions and methods of acidification”. Equine Veterinary Journal. 22 (2): 118–21. doi:10.1111/j.2042-3306.1990.tb04222.x. PMID2318175.