APA (7th ed.) Citation

Roll-Hansen, N. (2009). Sources of Wilhelm Johannsen's genotype theory.

Chicago Style (17th ed.) Citation

Roll-Hansen, Nils. Sources of Wilhelm Johannsen's Genotype Theory. 2009.

MLA (9th ed.) Citation

Roll-Hansen, Nils. Sources of Wilhelm Johannsen's Genotype Theory. 2009.

Warning: These citations may not always be 100% accurate.