)
https://scholar.google.com/citations?hl=en&user=AnAuM5MAAAAJ&view_op=list_works&sortby=pubdate#d=gs_md_cita-d&u=%2Fcitations%3Fview_op%3Dview_citation%26hl%3Den%26user%3DAnAuM5MAAAAJ%26sortby%3Dpubdate%26citation_for_view%3DAnAuM5MAAAAJ%3ApYRxIbzCxX0C%26tzom%3D-270
https://www.genealogy.math.ndsu.nodak.edu/id.php?id=93919