Zigo, F., M. Vasiľ, Z. Farkašová, S. Ondrašovičová, M. Zigová, J. Maľová, J. Výrostková, J. Bujok, and E. Pecka-Kiełb. “Impact of Humic Acid As an Organic Additive on the Milk Parameters and Occurrence of Mastitis in Dairy Cows”. Potravinarstvo Slovak Journal of Food Sciences, vol. 14, June 2020, pp. 358-64, doi:10.5219/1340.