Ualbai Utmakhanbetovich Umirbaev (on his 60th birthday). (English. Russian original) Zbl 1471.01037
Russ. Math. Surv. 76, No. 2, 373-378 (2021); translation from Usp. Mat. Nauk 76, No. 2, 187-192 (2021).
MSC:
01A70