On approximation of signals in Lip(α,r)-class using the product (N, pn,qn)(E,s)- summability means of conjugate Fourier series: On approximation of signals in $Lip(\alpha,r)$-class.. (2020). Nonlinear Studies, 27(2). https://nonlinearstudies.com/index.php/nonlinear/article/view/1575