Topchiev A., Zavgorodniy S., Pashkin Ya. Boron fluoride and its compounds as catalysts in organic chemistry. In Russian (ask us if in doubt)/Topchiev A., Zavgorodniy S., Paushkin Ya. Ftoristyy bor i ego soedineniya kak katalizatory v organicheskoy khimii. Academy of Sciences of the USSR 1956. 356 p. SKUalb1d5fe925359b6431.