Tkachenko, I., Kobzar, Y.L., Shekera О. and Shevchenko, V. 2025. Synthesis of 4,4′-bis(nonafluorobiphenyl-4-oxyphenyl)-bis(trifluoromethyl)methane and a ladder polyether with spirobisindane fragments on its base . Reports of the National Academy of Sciences of Ukraine. 7 (Feb. 2025), 116–122. DOI:https://doi.org/10.15407/dopovidi2015.07.116.