Internet, http://www.anb.org/articles/13/13-02363.html?, 2012-09-06
Information trouvée : 1891-1969, généticien, enseigne au Royal Agricultural College in Copenhagen, chercheur
aux USA
LCNA (CD), 1996-06
Plant evolution through amphiploidy and autoploidy with examples from the Madiinae
/ Jens Clausen, David D. Keck, William M. Hiesey, 1972