1. Technical University of Cluj Napoca, North University Center of Baia Mare, Department of Mathematics and Computer Science, Victoriei, Baia Mare, Romania
2. Department of Mathematics, Indira Gandhi National Tribal University, Lalpur, Amarkantak, Anuppur, Madhya Pradesh, India + L. Awadh Puri Colony Beniganj, (Phase-III), Opp.-I.T.I. Ayodhya Main Road, Faizabad, Uttar Pradesh, India