@article{RSMUP_1976__55__143_0,
     author = {Cellina, Arrigo},
     title = {A selection theorem},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {143--149},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {55},
     year = {1976},
     mrnumber = {474192},
     zbl = {0362.54010},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1976__55__143_0/}
}