1. Department of Mathematics, Government PG College, Joshimath, Chamoli (Uttarakhand), India
2. Department of Mathematics, Hemvati Nandan Bahuguna Garhwal University (HNBGU), SRT Campus Badshahithaul, Tehri Garhwal (Uttarakhand), India
3. Mathematical and Physical Science Foundation 4200, Slagelse, Denmark
4. Department of Mathematics, King Abdulaziz University, 21589 Jeddah, Saudi Arabia
5. Department of Mathematics, Government Degree College, Rudraprayag (Uttarakhand), India
6. Fachbereich Kontinuumsmechanik, University of Darmstadt, 64287 Darmstadt, Germany
7. Institute of Experimental Physics, Slovak Academy of Sciences, 043 53 Kosice, Slovakia
8. Institute of Physics, Silesian University in Opava, Bezruovo nm. 13, 746 01 Opava, Czech Rep.