Setälä, Jouko, Liisa Syrjälä-Qvist, and Esko Poutiainen. 1984. “Feeding of High Producing Dairy Cows According to Rumen Undegradable Protein Requirements in Grass Silage Based Diet”. Agricultural and Food Science 56 (1):73-82. https://doi.org/10.23986/afsci.72160.