An Introduction to Philosophy W. Russ Payne Bellevue College https://openlibrary-repo.ecampusontario.ca/jspui/bitstream/123456789/475/2/Intro-to-Phil-full-text.pdf
FUNDAMENTALS OF PHILOSOPHY David Stewart, H. Gene Blocker ,James Petrik (Ohio University) http://www.uop.edu.pk/ocontents/David%20Stewart_%20H.%20Gene%20Blocker_%20James%20Petrik%20-%20Fundamentals%20of%20Philosophy-Pearson%20(2012).pdf
Modern Philosophy This work is based on the work of Walter Ott & Alex Dunn