Synthesis of spiro[(6-phenyl-3,4-dihydro-2H-1,3-dioxine)-2R(S), 3′-(19′,28′-oxidooleanan)]-4-ones and X-ray diffraction analysis of their configuration / T. V. Rybalova [и др.] // Journal of Structural Chemistry. - 2005. - Т. 46, № 6. - С. 1126-1130 Доп.точки доступа: Rybalova, T. V.; Gatilov, Yu. V.; Nekrasov, D. D.; Tolstikov, A. G.; Rubtsov, A. E.