International Journal of Geometric Methods in Modern Physics (Int. J. Geom. Methods Mod. Phys.) (20160101), 13, no.~10, 1650124, 12~pp. ISSN: 0219-8878 (print).eISSN: 1793-6977.
International Journal of Geometric Methods in Modern Physics (Int. J. Geom. Methods Mod. Phys.) (20160101), 13, no.~1, 1550130, 11~pp. ISSN: 0219-8878 (print).eISSN: 1793-6977.