Whittall, J. B., Voelckel, C., Kliebenstein, D. J., & Hodges, S. A. (2006). Convergence,
constraint and the role of gene expression during adaptive radiation: floral anthocyanins in Aquilegia.
Molecular Ecology, 15(14), 4645-4657. doi:10.1111/j.1365-294X.2006.03114.x.