@article{ASNSP_1976_4_3_4_553_0,
     author = {Andreotti, A. and Nacinovich, M.},
     title = {Complexes of partial differential operators},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {553--621},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 3},
     number = {4},
     year = {1976},
     mrnumber = {445557},
     zbl = {0334.58015},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1976_4_3_4_553_0/}
}