Předmluva
O grupách, GDML_Books, (1974), p. 5-6 / Harvested from
@inbook{403811,
     title = {P\v redmluva},
     booktitle = {O grup\'ach},
     series = {GDML\_Books},
     publisher = {Mlad\'a fronta},
     address = {Praha},
     year = {1974},
     pages = {5-6},
     url = {http://dml.mathdoc.fr/item/403811}
}
 (éd.). Předmluva, dans O grupách, GDML_Books,  (1974), pp. 5-6. http://gdmltest.u-ga.fr/item/403811/