| 3HTT: reference: The hemagglutinin structure of an avian H1N1 influenza A virus., Lin T, Wang G, Li A, Zhang Q, Wu C, Zhang R, Cai Q, Song W, Yuen KY, Virology. 2009 Jul 21. PMID: 19628241 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).