GogoladzeL., & TsagareishviliV. (2017). Convergence of Fourier series of functions $\text{Lip} 1$ with respect to general orthonormal systems. Ukrains’kyi Matematychnyi Zhurnal, 69(4), 466-477. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/1710