Commutator structure of some subgroups of chevalley groups
Question 6.34 of the Kourov Notebook is solved: carry the familiar theorem of Merzlyakov on the joint commutator subgroup of covering subgroups over to Chevalley groups and moreover to orthogonal and unitary groups.
English version (Springer): Ukrainian Mathematical Journal 44 (1992), no. 6, pp 710-718.
Citation Example: Levchuk V. M. Commutator structure of some subgroups of chevalley groups // Ukr. Mat. Zh. - 1992. - 44, № 6. - pp. 786–795.