1W9X:
reference: Structure of a Bacillus halmapalus family 13 alpha-amylase, BHA, in complex with an acarbose-derived nonasaccharide at 2.1 A resolution., Davies GJ, Brzozowski AM, Dauter Z, Rasmussen MD, Borchert TV, Wilson KS, Acta Crystallogr D Biol Crystallogr. 2005 Feb;61(Pt 2):190-3. Epub 2005, Jan 19. PMID: 15681870

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