Setälä, Jouko, and Liisa Syrjälä-Qvist. “Untreated and Formaldehyde-Treated Urea As Nitrogen Sources for Lactating Dairy Cows”. Agricultural and Food Science 54, no. 1 (January 1, 1982): 43–52. Accessed August 16, 2024. https://journal.fi/afs/article/view/72088.