ALAKUKKU, L., A. RISTOLAINEN, and I. SARIKKA. “Surface Water Ponding on Clayey Soils Managed by Conventional and Conservation Tillage in Boreal Conditions”. Agricultural and Food Science 19, no. 4 (January 4, 2010): 313–326. Accessed June 23, 2021. https://journal.fi/afs/article/view/5994.