In this paper, we prove the existence of solutions of a nonlocal boundary value problem for nonlinear integro-differential equations of fractional order given by
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\begin{document}$$ \begin{array}{ll} ^cD^qx(t) = f(t,x(t),(\phi x)(t),(\psi x)(t)), \quad 0 < t < 1,\\x(0) = \beta x(\eta), x'(0) =0, x''(0) =0, \ldots, x^{(m-2)}(0) =0, x(1)= \alpha x(\eta), \end{array}$$\end{document}where \documentclass[12pt]{minimal}
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\begin{document}$${q \in (m-1, m], m \in \mathbb{N}, m \ge 2}$, $0< \eta <1$$\end{document} , and \documentclass[12pt]{minimal}
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\begin{document}$${\phi x}$$\end{document} and \documentclass[12pt]{minimal}
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\begin{document}$${\psi x}$$\end{document} are integral operators. The existence results are established by means of the contraction mapping principle and Krasnoselskii’s fixed point theorem. An illustrative example is also presented.