Lifjeld, J. T., Laskemoen, T., Kleven, O., Albrecht, T., & Robertson, R. J. (2010). Sperm Length Variation as a Predictor of Extrapair Paternity in Passerine Birds. Public Library of Science.

Lifjeld, Jan T., Terje Laskemoen, Oddmund Kleven, Tomas Albrecht, und Raleigh J. Robertson. Sperm Length Variation As a Predictor of Extrapair Paternity in Passerine Birds. Public Library of Science, 2010.

Lifjeld, Jan T., et al. Sperm Length Variation As a Predictor of Extrapair Paternity in Passerine Birds. Public Library of Science, 2010.