Clarence Irving Lewis - A scholarly treatment of this pragmatist thinker, by Eric Dayton. From the Internet Encyclopedia of Philosophy. - http://www.iep.utm.edu/l/lewisci.htm
Terry Peterson's Essays - Three essays to facilitate the understanding of C.I. Lewis's thought. Includes a page-by-page annotation of Mind and the World Order. - http://deming.ces.clemson.edu/pub/den/deming_peterson.htm