Roll-Hansen, N. Sources of Johannsen's Genotype Theory: Nils Roll-Hansen. Conference A Cultural History of Heredity III : 19th and early 20th centuries.(2005).
Chicago-referens (17:e uppl.)Roll-Hansen, Nils. "Sources of Johannsen's Genotype Theory: Nils Roll-Hansen." Conference A Cultural History of Heredity III : 19th and Early 20th Centuries.(2005) .
MLA-referens (8:e uppl.)Roll-Hansen, Nils. "Sources of Johannsen's Genotype Theory: Nils Roll-Hansen." Conference A Cultural History of Heredity III : 19th and Early 20th Centuries.(2005), .
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.