SOME CHEMICAL TRANSFORMATIONS OF CONDENSED TWO-RING SYSTEMS, THAT INCLUDE γ-LACTONE AND OXIRANE FRAGMENTS. Proc. YSU B: Chem. Biol. Sci. 2010, 44 (3 (223), 35-40. https://doi.org/10.46991/PYSUB.2010.44.3.035.