. "Wiedfeldt, Otto, 1871-1926" . . . . . . "Chōsa hōkokusho. Rōdō mondai" . . . "Minami Manshū Tetsudō Kabushiki Kaisha Chōsa hōkokusho. Zaisei" . . . "Schröder, Ernst Otto Wiedfeldt" . . . "Wiedfeldt, Otto, 1871-1926 Chōsen kōgyō shinkō saku" . . . "Wiedfeldt, Otto, 1871-1926 Die bewirtschaftung von korn" .