The book in the worker's breast pocket: 毛泽东选集 (Selected Works of Mao Zedong).
On the red flag: 上海市革命委员会 (Shanghai Revolutionary Committee).
The poster is 'signed' by three organizations:
上海工人革命造反总司令部 (Shanghai Workers' Revolutionary Rebel General Headquarters)
上海市灭资兴无铲修挺进军革命委员会 (Shanghai Municipal ??? Revolutionary Committee)
上海市房地局工人革命造反总指揮部 (Shanghai Real Estate Bureau Workers' Revolutionary Rebel Headquarters)