@inbook{400089,
     title = {[P\v redmluva]},
     booktitle = {Bernard Bolzano},
     series = {GDML\_Books},
     publisher = {Pra\v zsk\'a odbo\v cka D\v elnick\'e akademie v Praze II., Hybernsk\'a ul. 7},
     address = {Praha},
     year = {1937},
     pages = {[3]-[3]},
     url = {http://dml.mathdoc.fr/item/400089}
}