Links for Further Reading
1. Laplacian Derivations in Cylindrical and Spherical Coordinates
References
Editors, W. (2020, November 29). Laplace operator. Retrieved December 06, 2020, from https://en.wikipedia.org/wiki/Laplace_operator
Wang, R. (2018, December 12). The Laplace Operator. Retrieved December 06, 2020, from http://fourier.eng.hmc.edu/e161/lectures/gradient/node7.html