@article{CMH_1993__68_2_140321,
     author = {Dominique Arlettaz},
     title = {Exponents for extraordinary homology groups.},
     journal = {Commentarii mathematici Helvetici},
     pages = {653--672},
     publisher = {mathdoc},
     volume = {68},
     number = {2},
     year = {1993},
     zbl = {0968.55003},
     url = {http://geodesic.mathdoc.fr/item/CMH_1993__68_2_140321/}
}