1. L.V. Ahlfors, Conformal Invariants: Topics in Geometric Function Theory, McGraw-Hill Series in Higher Mathematics, 1973.
2. Symmetric decreasing rearrangement is sometimes continuous;Almgren;J. Amer. Math. Soc.,1989
3. A. Baernstein II, A unified approach to symmetrization, in: Partial differential equations of elliptic type (Cortona, 1992), Sympos. Math., XXXV, Cambridge University Press, Cambridge, 1994, pp. 47–91.
4. Spherical rearrangements, subharmonic functions, and *-functions in n-space;Baernstein;Duke Math. J.,1976
5. Sobolev inequalities, the Poisson semigroup and analysis on the sphere Sn;Beckner;Proc. Natl. Acad. Sci.,1992