1. Bhatt, Rajesh. Obligation and Possession. Papers from the UPenn/MIT Roundtable on Argument Structure and Aspect. Edited by: Harley, H. pp.21–40. Cambridge, MA: MITWPL.
2. Metaethical Contextualism Defended
3. Brennan, Virginia. 1993. “Root and Epistemic Modal Auxiliary Verbs”. Amherst: University of Massachusetts. Ph.D. Thesis