@article{AFM_1979_4_2_a10,
     author = {Matts Ess\'en and Daniel F. Shea},
     title = {On some questions of uniqueness in the theory of symmetrization},
     journal = {Annales Fennici Mathematici},
     pages = {311--340},
     publisher = {mathdoc},
     volume = {4},
     number = {2},
     year = {1979},
     doi = {10.5186/aasfm.1978-79.0404},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1978-79.0404/}
}