ISBN 978-0-8047-2629-0. Pawson, John R. Delaware Valley Rails: The Railroads and Rail Transit Lines of the Philadelphia Area. Willow Grove, Pennsylvania: John R. Pawson
(原始内容存档于2006-10-02). Figures from 2001, latest available Honolulu Transit. Honolulu Transit. 2012-11-18 [2012-11-23]. (原始内容存档于2012-11-06). Fred W. Frailey