@article{CMH_1964__39_139284,
     author = {Elon L. Lima},
     title = {Common {Singularities} of {Commuting} {Vector} {Fields} on 2-manifolds.},
     journal = {Commentarii mathematici Helvetici},
     pages = {97--110},
     publisher = {mathdoc},
     volume = {39},
     year = {1964},
     zbl = {0124.16101},
     url = {http://geodesic.mathdoc.fr/item/CMH_1964__39_139284/}
}