Affiliation: | (1) Department of Mathematics, Zakir Husain College, University of Delhi, Jawahar Lal Nehru Marg, New Delhi, 110002, India;(2) Department of Mathematics, University of Delhi, Delhi, 110007, India;(3) Centre for Fundamental Research in Space Dynamics and Celestial Mechanics, A-25, Rama Road, Adarsh Nagar, Delhi, 110033, India |