@article{RLIN_1991_9_2_2_a5,
     author = {Constantin, Adrian},
     title = {Some observations on a {Conti's} result},
     journal = {Atti della Accademia nazionale dei Lincei. Rendiconti Lincei. Matematica e applicazioni},
     pages = {137--145},
     publisher = {mathdoc},
     volume = {Ser. 9, 2},
     number = {2},
     year = {1991},
     zbl = {0732.34011},
     mrnumber = {9408},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RLIN_1991_9_2_2_a5/}
}