@article{ASNSP_1974_4_1_3-4_301_0,
     author = {Furi, M. and Martelli, M.},
     title = {A degree for a class of acyclic-valued vector fields in {Banach} spaces},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {301--310},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 1},
     number = {3-4},
     year = {1974},
     zbl = {0306.55009},
     mrnumber = {380874},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1974_4_1_3-4_301_0/}
}