@inbook{403039,
title = {11. \'Ulohy o \v case},
booktitle = {Aritmetick\'e hry a z\'abavy},
series = {GDML\_Books},
publisher = {Jednota \v cesk\'ych matematik\r u a fysik\r u},
address = {Praha},
year = {1942},
pages = {48-51},
url = {http://dml.mathdoc.fr/item/403039}
}
(éd.). 11. Úlohy o čase, dans Aritmetické hry a zábavy, GDML_Books, (1942), pp. 48-51. http://gdmltest.u-ga.fr/item/403039/