@article{RSMUP_1952__21__64_0,
     author = {Colombo, Giuseppe},
     title = {Sopra un sistema non-lineare in due gradi di libert\`a},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {64--98},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {21},
     year = {1952},
     mrnumber = {51997},
     zbl = {0047.33101},
     language = {it},
     url = {http://www.numdam.org/item/RSMUP_1952__21__64_0/}
}