@article{GDZPPN002095386, title = {Busemann Functions and Total Curvature.}, journal = {Inventiones mathematicae}, volume = {55}, year = {1979}, pages = {281-297}, zbl = {0433.53050}, url = {http://dml.mathdoc.fr/item/GDZPPN002095386} }
Shiohama, Katsuhiro. Busemann Functions and Total Curvature.. Inventiones mathematicae, Tome 55 (1979) pp. 281-297. http://gdmltest.u-ga.fr/item/GDZPPN002095386/