Makio Tamura Donna K. Hendrix Peter S. Klosterman Nancy R. B. Schimmelman Steven E. Brenner Stephen R. Holbrook SCOR: Structural Classification of RNA, version 2.0. 182-184 2004 32 Nucleic Acids Research Database-Issue db/journals/nar/nar32.html#TamuraHKSBH04 http://dx.doi.org/10.1093/nar/gkh080