Filtering by: File Format video/mp4 Remove constraint File Format: video/mp4 File Format video/x-msvideo Remove constraint File Format: video/x-msvideo Resource Type moving image Remove constraint Resource Type: moving image Subject antarctica--aerial exploration Remove constraint Subject: antarctica--aerial exploration Subject airplanes Remove constraint Subject: airplanes Subject hearst, william randolph, 1908 Remove constraint Subject: hearst, william randolph, 1908 Time Period (Topic) 1930s (1930-1939) Remove constraint Time Period (Topic): 1930s (1930-1939)