@inbook{400073,
     title = {On Bolzano's function},
     booktitle = {Bolzano and the Foundations of Mathematical Analysis},
     series = {GDML\_Books},
     publisher = {Society of Czechoslovak Mathematicians and Physicists},
     address = {Praha},
     year = {1981},
     pages = {67-81},
     url = {http://dml.mathdoc.fr/item/400073}
}