Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910: The New York Tunnel Extension of the Pennsylvania Railroad.; The Cross-Town Tunnels. Paper No. 1158 | Digital Library | PAMCET

Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910: The New York Tunnel Extension of the Pennsylvania Railroad.; The Cross-Town Tunnels. Paper No. 1158 | Digital Library | PAMCET | PAMCET