Gunko MS, Babenko VF, Parfinovych NV. Optimal recovery of elements from Hilbert space and their scalar products by Fourier coefficients known with error. Ukr. Mat. Zhurn. [Internet]. 2020Jun.17 [cited 2024Apr.19];72(6):736-50. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/1107