Посилання:Radical functors in the category of modules over different rings / N. Burban, O. Horbachuk // Algebra and Discrete Mathematics. — 2008. — Vol. 7, № 3. — С. 30–39. — Бібліогр.: 8 назв. — англ.
The category G of all left modules over all rings is studied. Necessary and sufficient conditions for a preradical functor on G to be radical are given. Radical functors on essential subcategories of G are investigated.