@UNPUBLISHED{publication1, title = "Symmetric semi-classical orthogonal polynomials of class one on q-quadratic lattices", author = "{FILIPUK, Galina} and {REBOCHO, Maria das Neves}", year = "2018-09-16", abstract = " In this paper we study discrete semi-classical orthogonal polynomials on non-uniform lattices. In the symmetric class one case we give a closed form expression for the recurrence coefficients of orthogonal polynomials. ", url = "http://www.mat.uc.pt/preprints/eng\_2018.html", note = "" }