Cortese, Dan; Mills, Fred (18 Julai 2018). "What is a Skyscraper?". TheB1M. Dicapai pada 7 November 2020.
worldcat.org
Landau, Sarah; Condit, Carl W. (1996). Rise of the New York Skyscraper, 1865–1913. Yale University Press. ISBN978-0-300-07739-1. OCLC32819286.
Condit, Carl W. (1968). American Building: Materials and Techniques from the Beginning of the Colonial Settlements to the Present. Chicago, A.S & London, U.K: University of Chicago Press. m/s. 115. OCLC600614625.