@article{RSMUP_1981__65__129_0,
     author = {Morgantini, Edmondo},
     title = {Una curiosa propriet\`a metrica dei quadrilateri piani completi},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {129--133},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {65},
     year = {1981},
     mrnumber = {653289},
     zbl = {0482.51016},
     language = {it},
     url = {http://archive.numdam.org/item/RSMUP_1981__65__129_0/}
}