Brown, W. L. H. Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 The New York Tunnel Extension of the Pennsylvania Railroad. The North River Tunnels. Paper No. 1155.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBrown, W. L.; Hewett. Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 The New York Tunnel Extension of the Pennsylvania Railroad. The North River Tunnels. Paper No. 1155.
एमएलए (9वां संस्करण) प्रशस्ति पत्रBrown, W. L.; Hewett. Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 The New York Tunnel Extension of the Pennsylvania Railroad. The North River Tunnels. Paper No. 1155.
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