Books, Brochures, and Chapters>Book:  Kirk , Raven , Schofield (1984-02-24), The Presocratic Philosophers: A Critical History with a Selection of Texts, Cambridge University Press, Retrieved on 2011-09-06

Books, Brochures, and Chapters>Book:  Jefferson , Thomas (2011-05-05), Notes on the State of Virginia, BiblioLife, Retrieved on 2011-06-15

Source Material [etext.virginia.edu]

Books, Brochures, and Chapters>Book:  Newton , Isaac (2010-02-01), The Principia: Mathematical Principles of Natural Philosophy, www.snowballpublishing.com, Retrieved on 2011-06-05

Books, Brochures, and Chapters>Book:  Sachs , Joe (1995-03-01), Aristotle's Physics: A Guided Study (Masterworks of Discovery), Rutgers University Press, Retrieved on 2011-05-31

Source Material [classics.mit.edu]

Books, Brochures, and Chapters>Book:  Kramnick , Isaac (1995-12-01), The Portable Enlightenment Reader (The Viking Portable Library), Penguin (Non-Classics), Retrieved on 2011-05-30

Books, Brochures, and Chapters>Book:  Clifford , William K. (1999-05), The Ethics of Belief & Other Essays (Great Books in Philosophy), Prometheus Books, Retrieved on 2011-05-17

Source Material [www.infidels.org]

Books, Brochures, and Chapters>Book:  Dickens , Charles (2010-09-23), (The Original) To be Taken with a Grain of Salt, ADB Publishing, Retrieved on 2011-05-17

Source Material [www.lang.nagoya-u.ac.jp]