Ullah, Inayat, Saleem Iqbal, Farhana Sarwar, and Abdul Rehman. 2019. “N-Dimensional Fractional Fourier Transform and Its Eigenvalues and Eigenfunctions”. American Scientific Research Journal for Engineering, Technology, and Sciences 62 (1): 210-14. https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/5494.