Professor Vadim Mikhailovich Chubko was a notable member of The Group. He is mentioned in a document in S.T.A.L.K.E.R.: Shadow of Chernobyl. Described by Captain D. F. Maksimenko as infamous, Professor Chubko was apparently instrumental in running the clandestine research in the Zone. One of his closest associates was Doctor Petr Strizh of the Agroprom Research Institute, who was procuring rare, hard to get equipment for the researchers of The Group.