Pálinkó István; Forgó Péter: Unexpected nonplanar quinoidal substructure in an abietane terpene from Salvia candelabrum—an ab initio computational search for the simplest substitution pattern causing the nonplanarity. Journal of Molecular Structure: THEOCHEM, 717 (1-3). pp. 153-155. ISSN 01661280 (2005)