Books, Brochures, and Chapters>Book:  Kant, Immanuel (1952), The Critique of Pure Reason ; The Critique of Practical Reason and Other Ethical Treatises ; The Critique of Judgement, Forgotten Books, Retrieved on 2012-06-07

Source Material [books.google.com]

Books, Brochures, and Chapters>Brochure/Pamphlet:  Kant, Immanuel (1784), What is Enlightenment?, Retrieved on 2011-05-30

Source Material [www.english.upenn.edu]