@inbook{402980,
title = {4. Involuce na kru\v znici},
booktitle = {Imagin\'arn\'\i\ elementy v geometrii},
series = {GDML\_Books},
publisher = {Jednota \v cesk\'ych matematik\r u a fysik\r u},
address = {Praha},
year = {1941},
pages = {27-33},
url = {http://dml.mathdoc.fr/item/402980}
}
(éd.). 4. Involuce na kružnici, dans Imaginární elementy v geometrii, GDML_Books, (1941), pp. 27-33. http://gdmltest.u-ga.fr/item/402980/