D. A. Gasparini, « Battery-Joralemon Street Tunnel », Journal of Performance of Constructed Facilities, American Society of Civil Engineers, vol. 20, no 1, , p. 92–107 (lire en ligne, consulté le ).
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(en) New York City Transit: A Memorandum Addressed to the Public Service Commission of the First District, City Club of New York, (lire en ligne).
nydailynews.com
Michael Aronson, « The Digger Clifford Holland », Daily News, New York, (lire en ligne, consulté le ).
