1. Symmetry and related properties via the maximum principle
2. B. Gidas, W. M. Ni and L. Nirenberg, symmetry of positive solutions of nonlinear elliptic equations in Rn, Mathematical Analysis and Applications Part A, ed. by L. Nachbin, adv. Math. Suppl. Stud. 7, Academic Press, New York, pp 369–402(1981),.
3. On the asymptotic behavior and radial symmetry of positive solutions of semilinear elliptic equations in R n II. Radial symmetry
4. Symmetry results for semilinear elliptic equations in R2
5. D. B. Dhaigude, D. P. Patil, Symmetry properties of solutions of nonlinear elliptic equations, International journal of Advances in Management, Technology and Engineering Sciences, Vol. II, 10(11), (2013) pp 24 – 28.