Kushpel' Alexander K

Publications in Math-Net.Ru

1. Sharp estimates of the widths of convolution classes
   
   Izv. Akad. Nauk SSSR Ser. Mat., 52:6 (1988),  1305–1322
2. Sharp estimates of the widths of convolution classes in the space $C_{2\pi}$
   
   Trudy Mat. Inst. Steklov., 180 (1987),  148–149