On Formally Undecidable Propositions of Principia Mathematica ...
Kurt Gödel
Encyclopedia of Philosophy
Donald M. Borchert
Knowledge in Ancient Philosophy
Nicholas D. Smith
Heidegger's Philosophy of Being: A Critical Interpretation
Herman Philipse
Historical Dictionary of Ancient Greek Philosophy
Anthony Preus
What is Wrong with Us?
Coombes, Eric; Dalrymple, Theodore; & Theodore Dalrymple
Adam Smith
James R. Otteson