@article{ASNSP_1981_4_8_3_365_0,
     author = {Andreotti, Aldo and Fredricks, Gregory and Nacinovich, Mauro},
     title = {On the absence of {Poincar\'e} lemma in tangential {Cauchy-Riemann} complexes},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {365--404},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 8},
     number = {3},
     year = {1981},
     mrnumber = {634855},
     zbl = {0482.35061},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1981_4_8_3_365_0/}
}