Knief, U., Schielzeth, H., Kempenaers, B., Ellegren, H., & Forstmeier, W. (2012). QTL and quantitative genetic analysis of beak morphology reveals patterns of standing genetic variation in an Estrildid finch. Molecular Ecology, 21(15), 3704-3717. doi:10.1111/j.1365-294X.2012.05661.x.