K. S. Vishnevetskiy, “On the Coincidence of Pure Greedy and Best $m$-Term Approximations”, Mat. Zametki, 111:2 (2022), 202–210; Math. Notes, 111:2 (2022), 204–210
K. S. Vishnevetskiy, “Condition of coincidence between greedy approximations and $m$-term ones”, Vestnik Moskov. Univ. Ser. 1. Mat. Mekh., 2022, no. 2, 18–23; Moscow University Mathematics Bulletin, 77:2 (2022), 67–72