@article{CMH_1984__59_139969,
     author = {N. Habegger and V. Jones and O.P. Ortiz},
     title = {Relative cohomolgy of groups.},
     journal = {Commentarii mathematici Helvetici},
     pages = {149--164},
     publisher = {mathdoc},
     volume = {59},
     year = {1984},
     zbl = {0544.20047},
     url = {http://geodesic.mathdoc.fr/item/CMH_1984__59_139969/}
}