Er, Adil, Andersen isn't the only source that backs this up.  The fact that Armenia once had full control of all the territory of the Kazakh uyezd is mentioned in works by A.B. Kadishev, Artur Tsutsiev, and seen on the maps of Atlas Istorii SSR by Konstantin Bazilevich (where Armenia is clearly showing having a boundary on the Kura River).  As a matter of fact, here's a map from Tsutsiev's book which clearly shows how the territory looked prior to 1931:

Adil, your Azerbaijani sources are not credible for the very fact that they are Azerbaijani sources and that they hold a bias.  My sources are all NPOV.