“…And there have been many results on existence and uniqueness of the solution of boundary value problems for fractional differential equations. For example, fractional boundary value problems at resonance [1,5,27,39,40], Caputo fractional derivative problems [11,23,37], impulsive problems [2,15,29,41], multi-point problems [1, 5, 21, 22, 27-29, 31, 40], integral boundary value problems [6,12,13,15], fractional p-Laplace problems [8,10,14,21,22,35,36], fractional lower and upper solution problems [4,7,30,38], fractional delay problems, [24,33,34], solitons [9], singular problems [3], etc.…”