%0 Journal Article %A Schafer, James A. %T Representing Homology Classes on Surfaces %J Canadian mathematical bulletin %D 1976 %P 373-374 %V 19 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1976-058-4/ %R 10.4153/CMB-1976-058-4 %F 10_4153_CMB_1976_058_4