Novikov, S. I. (1999). Approximation of one class of differentiable functions by piecewise-Hermitian<em class="a-plus-plus">L</em&gt;-splines. Ukrains’kyi Matematychnyi Zhurnal, 51(11), 1495–1504. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/4751