@article{RSMUP_1970__44__85_0,
     author = {Katz, M. and Schnitzer, F.},
     title = {On a problem of {J.} {Schnitzer}},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {85--90},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {44},
     year = {1970},
     mrnumber = {299492},
     zbl = {0235.26004},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1970__44__85_0/}
}