Kalita EA. Exactness of the cordes condition of the Hölder property for the gradient of nondivergent elliptic systems. Ukr. Mat. Zhurn. [Internet]. 1995 Feb. 25 [cited 2025 Apr. 7];47(2):292–294. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5415