1. A. Atangana, Appl. Math. Comput. 273, 948 (2016)
2. M. Caputo, M. Fabrizio, Progr. Fract. Differ. Appl. 1, 73 (2015)
3. E.F. Doungmo Goufo, M.K. Pene, N. Jeanine, Open Math. 13, 839 (2015)
4. J.F. Gómez-Aguilar, H. Ypez-Martnez, C. Caldern-Ramn, I. Cruz-Ordua, R.F. Escobar-Jimnez, R.F. Escobar-Jimnez, Entropy 17, 6289 (2015)
5. J. Losada, J.J. Nieto, Progr. Fract. Differ. Appl. 1, 87 (2015)