David Franzen, A History of Phosphate Export from North Dakota, North Dakota State University, Center for Regional Climate Studies (CRCS), 2020-05-05, https://www.youtube.com/watch?v=BOyc2p-My1w&feature=youtu.be, Soil Health Webinar Series, NDSU Langdon Research Extension Center, NDSU Soil Health Team

David Franzen, A History of Phosphate Export from North Dakota, North Dakota State University, Center for Regional Climate Studies (CRCS), 2020-05-05, https://www.youtube.com/watch?v=BOyc2p-My1w&feature=youtu.be, Soil Health Webinar Series, NDSU Langdon Research Extension Center, NDSU Soil Health Team