Independent axes of genetic variation and parallel evolutionary divergence of opercle bone shape in threespine stickleback.
Kimmel CB, Cresko WA, Phillips PC, Ullmann B, Currey M, von Hippel F, Kristj?nsson BK, Gelmond O, McGuigan K. Independent axes of genetic variation and parallel evolutionary divergence of opercle bone shape in threespine stickleback. Evolution. 2012 Feb; 66(2):419-34.