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