"RIPLEY, William Zebina," in Albert Nelson Marquis, ed., Who's Who In New England (Chicago: A.N. Marquis & Co., 1916) , p. 909.
bts.gov
ntl.bts.gov
See Appendix B, "Review of Recent Railroad Merger History" in United States Congress, Office of Technology Assessment, A Review of National Railroad Issues (NTIS Order #PB-250622, December 1975). [2]Archivado el 16 de junio de 2017 en Wayback Machine.
doi.org
dx.doi.org
Cravens, H. (1996). «"Scientific racism in modern America, 1870s–1990s"». Prospects. 21: 471-490. doi:10.1017/S0361233300006633.|fechaacceso= requiere |url= (ayuda)
«'More Merciful and Not Less Effective': Eugenics and Economics in the Progressive Era». Historical of Political Economy35 (4): 687-712. 2003. Discussion of Ripley's work on p. 690. [1].
See Appendix B, "Review of Recent Railroad Merger History" in United States Congress, Office of Technology Assessment, A Review of National Railroad Issues (NTIS Order #PB-250622, December 1975). [2]Archivado el 16 de junio de 2017 en Wayback Machine.