@article{MM2_1977__23_154512,
     author = {Michel Zisman},
     title = {Un th\'eor\^eme sur les sommes amalgam\'ees de groupes simpliciaux.},
     journal = {Manuscripta mathematica},
     pages = {125--130},
     publisher = {mathdoc},
     volume = {23},
     year = {1977},
     zbl = {0374.18009},
     url = {http://geodesic.mathdoc.fr/item/MM2_1977__23_154512/}
}