TY - BOOK ED - University of Illinois. Engineering Experiment Station TI - [Twelfth progress report]: investigation of prestressed rei-nforced concrete for highway bridges / prepared as a part o-f an investigation conducted by the Engineering Experiment -Station University of Illinois ; in cooperation with the Di-vision of Highway State of Illinois and U.S. Department of -Commerce, Bureau of Public Roads CY - Urbana, Ill. : University of Illinois ER -