BlattH. P., GrothmannR., & KovachevaR. K. (2006). Sign changes in rational <i>L_w</i><sup>1</sup&gt;-approximation. Ukrains’kyi Matematychnyi Zhurnal, 58(2), 283–287. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3452