@article{SM_2007_198_11_a1,
     author = {V. V. Volchkov},
     title = {Local two-radii theorem in symmetric spaces},
     journal = {Sbornik. Mathematics},
     pages = {1553--1577},
     publisher = {mathdoc},
     volume = {198},
     number = {11},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2007_198_11_a1/}
}