1. The Nature of Legal Philosophy;R Alexy;Ratio Juris,2004
2. On the Concept and the Nature of Law;R Alexy;Ratio Juris,2008
3. Raz on Necessity;B Bix;Law and Philosophy,2003
4. Looking for the Nature of Law: On Shapiro's Challenge;D Canale;Law and Philosophy,2011
5. Does Conceivability Entail Possibility?;D Chalmers;Conceivability and Possibility,2002