@article{AGMS_2015_3_1_a7,
     author = {Ketterer, Christian},
     title = {Obata{\textquoteright}s {Rigidity} {Theorem} for {Metric} {Measure} {Spaces}},
     journal = {Analysis and Geometry in Metric Spaces},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {2015},
     zbl = {1327.53051},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AGMS_2015_3_1_a7/}
}