Bularas Driss

Publications in Math-Net.Ru

1. The problem of the center “in the large” for a general quadratic system
   
   Dokl. Akad. Nauk SSSR, 311:4 (1990),  777–780
2. Solution of a problem of the center “in the large” for a general quadratic differential system
   
   Differ. Uravn., 25:11 (1989),  1856–1862
3. Concomitants of a system with quadratic nonlinearities
   
   Differ. Uravn., 14:5 (1978),  835–842