[1] H. W. Turnbull, The correspondence of Isaac Newton, vol. 1, New York: Cambridge University Press, 1959, p. 416.
[2] C. Chen, Mapping Scientific Frontiers: The Quest for Knowledge Visualization, Springer, 2003, p. 135.
[3] The Quotation page, Quotation Details, “Sir Isaac Newton, in a letter to Robert Hooke, (February 5, 1675)”, http:// www.quotationspage.com/quote/862.html (accessed Jan 31, 2013).
[4] StanleyScott, Connections: The EERI Oral History Series, Egor P. Popov, Earthquake Engineeing Research Institute, 2001.
[5] Photograph by Ed Kirwan Graphic Arts, 2440 Bancroft Way, Berkeley, California, Courtesy of the Department of Civil Engineering, UC Berkeley.
