Romao, MJ, I. Kolln, JM Dias, AL Carvalho, A. Romero, P. F. Varela, L. Sanz, E. Topfer-Petersen, and JJ Calvete. "Crystal structure of acidic seminal fluid protein (aSFP) at 1.9 angstrom resolution: a bovine polypeptide of the spermadhesin family." Journal of Molecular Biology. 274 (1997): 650-660.