 Notable Vesnin alumni of this period include Andrey Burov (class of 1925), Mikhail Barsch (1926), Ivan Leonidov (1927) and Georgy Krutikov (1928).In December 1925 short-lived artistic unions based at Vkhutemas, MVTU and Institute of Civil Engineers merged into a new organization, OSA Group, headed by Ginzburg and Alexander Vesnin.They recruited the formerly independent Ilya Golosov and Konstantin Melnikov, making OSA the most representative left-wing architectural group since inception.