Numerical solutions of interval-valued fractional nonlinear differential equations Lan-Lan Huang, Bao-Qing Liu, Dumitru Baleanu and Guo-Cheng Wu Eur. Phys. J. Plus, 134 5 (2019) 220 Published online: 23 May 2019 DOI: 10.1140/epjp/i2019-12746-3