“An American Inventor”. Garrett A. Morgan Technology and Transportation Futures Program. Federal Highway Administration. January 15, 2012時点のオリジナルよりアーカイブ。December 6, 2011閲覧。
“An American Inventor”. Garrett A. Morgan Technology and Transportation Futures Program. Federal Highway Administration. January 15, 2012時点のオリジナルよりアーカイブ。December 6, 2011閲覧。