An Interpretive Review of 20th US Machining and Grinding Research (M. Eugene Merchant. Cincinnati, Ohio: Techsolve, Inc. 2003)[2]Arquivado em 2009-02-05 no Wayback Machine
Carl G. Barth, 1860–1939: A Sketch (Florence M. Manning. Norwegian-American Historical Association. Volume XIII: Page 114 [1]Arquivado em 2017-07-05 no Wayback Machine
web.archive.org
Carl G. Barth, 1860–1939: A Sketch (Florence M. Manning. Norwegian-American Historical Association. Volume XIII: Page 114 [1]Arquivado em 2017-07-05 no Wayback Machine
An Interpretive Review of 20th US Machining and Grinding Research (M. Eugene Merchant. Cincinnati, Ohio: Techsolve, Inc. 2003)[2]Arquivado em 2009-02-05 no Wayback Machine
wilsonquarterly.com
archive.wilsonquarterly.com
Drucker, P. F. (1993). The Rise of the Knowledge Society. [3] The Wilson Quarterly, 17(2), 52–71. doi:10.2307/40258682