@article{ASENS_1997_4_30_5_595_0,
     author = {Guijarro, Luis and Petersen, Peter},
     title = {Rigidity in non-negative curvature},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     pages = {595--603},
     publisher = {Elsevier},
     volume = {Ser. 4, 30},
     number = {5},
     year = {1997},
     doi = {10.1016/s0012-9593(97)89933-8},
     mrnumber = {98i:53047},
     zbl = {01088814},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/s0012-9593(97)89933-8/}
}