Kumari, Reena2017-11-172017-11-172014-10http://hdl.handle.net/123456789/698enCollinear pointsCollinear equilibrium pointsNon-collinear equilibrium pointsZero velocity surfacesFitting function for periodic orbitAMTPh.DStability of periodic orbits in the modified restricted three and four body problems with perturbing forcesThesis