Patel, N. V., and V. M. Shah. “On the Order of Fourier Coefficients of a Lacunary Fourier Series”. The Journal of the Indian Mathematical Society 53, no. 1-4 (December 1, 1988): 209–215. Accessed May 7, 2024. http://informaticsjournals.com/index.php/jims/article/view/22007.