Natural Bridge — the oldest high school west of the Mississippi River. Jeannette Batz Cooperman. 'There Will Always Be a Central High School'. St. Louis Post-Dispatch
Transaction of the Academy of Science of St. Louis. 1904, 14 (5): 123–170 (英语). http://paleodb.org/cgi-bin/bridge.pl?action=displayCollectionDetails&collection_no=7438