@inbook{400148,
title = {Vorrede},
booktitle = {Bernard Bolzano's Schriften},
series = {GDML\_Books},
publisher = {Kr\'alovsk\'a \v cesk\'a spole\v cnost nauk v Praze},
address = {Praha},
year = {1930},
pages = {VII-XVI},
url = {http://dml.mathdoc.fr/item/400148}
}
Petr, Karel. Vorrede, dans Bernard Bolzano's Schriften, GDML_Books, (1930), pp. VII-XVI. http://gdmltest.u-ga.fr/item/400148/