“…For the existence and multiplicity results on fractional Laplacian, readers can refer to [24] and references therein. For the doubly nonlocal problem, precisely, the nonlocal elliptic equation involving fractional Laplacian and Choquard type nonlinearity, there are articles which discuss the existence and multiplicity of solutions, we cite [3,11,29,37] and references therein, with no attempt to provide a complete list.…”