@article{CMH_1993__68_2_140318,
     author = {R. Brooks and P. Perry and Petersen V and P.},
     title = {On {Cheeger's} inequality.},
     journal = {Commentarii mathematici Helvetici},
     pages = {599--621},
     publisher = {mathdoc},
     volume = {68},
     number = {2},
     year = {1993},
     zbl = {0809.53049},
     url = {http://geodesic.mathdoc.fr/item/CMH_1993__68_2_140318/}
}