@inbook{401367,
     title = {8. O faktoroidech},
     booktitle = {\'Uvod do teorie grup},
     series = {GDML\_Books},
     publisher = {Kr\'alovsk\'a \v cesk\'a spole\v cnost nauk},
     address = {Praha},
     year = {1944},
     pages = {36-41},
     url = {http://dml.mathdoc.fr/item/401367}
}