Effects of potassium dichromate and sample storage time on fat and protein by Milko-Scan and on protein and casein by a modified Pro-Milk Mk II method Ng-Kwai-Hang, K.F.; Hayes, J.F. Journal of Dairy Science 65(10): 1895-1899 1982 https://eurekamag.com/research/001/071/001071860.php