"The Art Of Choosing: The Decisions We Make Everyday of our Lives, What They Say About Us and How We Can Improve Them". Book by Sheena Iyengar, March 2010.
"A Primer on Environmental Decision-Making: An Integrative Quantitative Approach". Book by Knut Lehre Seip, Fred Wenstop, Springer Science & Business Media, p. 184, 2006.
Charles Proteus Steinmetz, Joseph Le Roy Hayden (1917). “Steinmetz Electrical Engineering Library: Engineering mathematics; a series of lectures delivered at Union college (3rd ed. 1917)”
Percy Bysshe Shelley (1821). “Queen Mab, a philosophical poem, with notes. [reputed to have been given by the author to W. Francis. Wanting the title-leaf, dedication and part of the last leaf].”, p.173