SCOR: Structural Classification of RNA, version 2.0. - Makio Tamura; Donna K. Hendrix; Peter S. Klosterman; Nancy R. B. Schimmelman; Steven E. Brenner; Stephen R. Holbrook (Nucleic Acids Res., 2004)

MeRNA: a database of metal ion binding sites in RNA structures. - Liliana R. Stefan; Rui Zhang 017; Aaron G. Levitan; Donna K. Hendrix; Steven E. Brenner; Stephen R. Holbrook (Nucleic Acids Res., 2006)