Wurtele, J.; Wurtele, J.; Friedman, A.; Grote, D.P.; Vay, J-L. & Gomberoff, K. A method for obtaining three-dimensional computation equilibrium of non-neutral plasmas using WARP, article, March 25, 2006; (https://digital.library.unt.edu/ark:/67531/metadc897957/m1/1/: accessed January 22, 2019), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .