E. N. Shcherbakova, T. B. Karyagina, and Y. G. Popov, “SYNTHESIS OF NAPHTHOQUINONES IN THE ISOLATED CULTURE OF $ALKANNA~ORIENTALIS$”, Proc. YSU B: Chem. Biol. Sci., vol. 39, no. 2 (207), pp. 100–105, Jun. 2005.