Gavriil Semikolenov.  Etyudy po geometrii Lobachevskogo Etyud 1: Teorema Pifagora v geometrii Lobachevskogo./Gavriil Semikolov. Studies on Lobachevsky geometry Study 1: Pythagoras theorem in Lobachevsky geometry. In Russian (ask us if in doubt) - landofmagazines.com

TransliterationGavriil Semikolenov.  Etyudy po geometrii Lobachevskogo Etyud 1: Teorema Pifagora v geometrii Lobachevskogo.

In EnglishGavriil Semikolov. Studies on Lobachevsky geometry Study 1: Pythagoras theorem in Lobachevsky geometry. In Russian (ask us if in doubt)

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