Relativistic Gravitational mass in Tolman-VI type solution
  Some known solutions for static charged fluid spheres of Tolman-VI type in general relativity are reexamined. The gravitational mass that appears in the Pant and Sah \cite{pan79} and Tikekar \cite{tik84} solutions is shown to be of electromagnetic origin in the sense that the gravitational mass, along with all other physical quantities, depends on the electromagnetic field alone. The energy condition, singularity and stability problems of the models are discussed thoroughly. 
Saibal Ray and Basanti Das