Barrios, Melani, and Gabriela Reyero. “An Euler-Lagrange Equation Only Depending on Derivatives of Caputo for Fractional Variational Problems With Classical Derivatives”. Statistics, Optimization & Information Computing 8, no. 2 (May 18, 2020): 590-601. Accessed March 29, 2024. http://www.iapress.org/index.php/soic/article/view/865.