1DOT:
reference: Structure of diferric duck ovotransferrin at 2.35 A resolution., Rawas A, Muirhead H, Williams J, Acta Crystallogr D Biol Crystallogr. 1996 Jul 1;52(Pt 4):631-40. PMID: 15299626

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).