@article{ASNSP_1983_4_10_4_587_0,
     author = {Talenti, Giorgio},
     title = {On functions, whose lines of steepest descent bend proportionally to level lines},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {587--605},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 10},
     number = {4},
     year = {1983},
     mrnumber = {753157},
     zbl = {0542.35007},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1983_4_10_4_587_0/}
}