@article{Król_J._Effect_2013,
 author={Król, J. and Brodziak, A. and Litwińczuk, Z. and Litwińczuk, A.},
 number={No 2},
 howpublished={online},
 journal={Polish Journal of Veterinary Sciences},
 year={2013},
 publisher={Polish Academy of Sciences Committee of Veterinary Sciences},
 publisher={University of Warmia and Mazury in Olsztyn},
 title={Effect of age and stage of lactation on whey protein content in milk of cows of different breeds},
 doi={10.2478/pjvs-2013-0055},
}