Liverpool Overhead Railway motor coach number 3, 1892 National Museums Liverpool. ”This is one of the original motor coaches which has electric motors mounted beneath the floor, a driving cab at one end and third class accommodation with wooden seats.” Viitattu 21.1.2011.
nytimes.com
Frank Sprague: Mr Sprague answers Mr Westinghouse. The New York Times, 18.1.1902. Artikkelin verkkoversio. Viitattu 16.6.2012.