When Zelmanov began to work on the Restricted Burnside problem there were two major difficulties in pushing what had been achieved for n = p to n = pk. Firstly it there was no reduction of the problem to Lie algebras with the Engel condition, This Zelmanov achieved in 1989.
Kapag Zelmanov ay nagsimulang magtrabaho sa Renendahan Burnside problema ay may dalawang malaking problema sa kung ano ang pagtutulak had been makakamtan para sa n = p sa n = p k. Muna ito ng walang pagbabawas ng problema sa humiga / magsinungaling algebras sa Engel condition, Ang Zelmanov makakamtan sa 1989.