Korneichuk NP. Permutations and piecewise-constant approximation of continuous functions of <em class="a-plus-plus">n</em> variables. Ukr. Mat. Zhurn. [Internet]. 1998Jul.25 [cited 2024Nov.24];50(7):907–918. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4871