@article{CMH_1957__32_139157,
     author = {Andr\'e Haefliger},
     title = {Structures feuillet\'ees et cohomologie \`a valeur dans un faisceau de groupoides.},
     journal = {Commentarii mathematici Helvetici},
     pages = {248--329},
     publisher = {mathdoc},
     volume = {32},
     year = {1957},
     zbl = {0085.17303},
     url = {http://geodesic.mathdoc.fr/item/CMH_1957__32_139157/}
}