@inbook{402756, title = {Dvoj\'\i\ geometrie}, booktitle = {Z\'aklady neeukleidovsk\'e geometrie Loba\v cevsk\'eho}, series = {GDML\_Books}, publisher = {P\v r\'\i rodov\v edeck\'e nakladatelstv\'\i }, address = {Praha}, year = {1953}, pages = {88-105}, url = {http://dml.mathdoc.fr/item/402756} }
(éd.). Dvojí geometrie, dans Základy neeukleidovské geometrie Lobačevského, GDML_Books, (1953), pp. 88-105. http://gdmltest.u-ga.fr/item/402756/