Self-gravitating charged fluid spheres with anisotropic pressures
  The coupled system of the spherically symmetric Einstein--Maxwell differential equations is solved under two different source conditions: non-zero electric charge and pressure anisotropy. Expressions for the metric functions, and pressures which extend the Tolman VII exact solution are deduced from the new solutions. By applying boundary conditions to these solutions, all integration constants are computed in terms of parameters that are physically meaningful. 
Ambrish M. Raghoonundun and David W. Hobill
gr-qc