George W. Hutchison Professor of Energy Law, S.M.U. (1987- ); Hon. Lecturer, Centre for Energy, Petroleum and Mineral Law, University of Dundee (2000-); Senior Fellow, University of Melbourne (2007-); Visiting Professor of Law, University of Sydney (2008-2016); Visiting Professor, University de ESAN (2008); Fulbright Senior Specialist and Visiting Borden Ladner Gervais LLP Chair of Energy Law and Policy, University of Alberta (2008); Visiting Professor, University Agostinho Neto (2009); Visiting Professor, Chulalongkorn University (2010, 2012); Visiting Professor of Law, University of New Mexico (1996); Visiting Professor of Natural Resources Law, University of Denver (1987); Professor of Law, University of Tulsa (1978-1987); Visiting Professor of Law, S.M.U. (1984); Visiting Professor of Law, University of Texas (1983); Associate Professor of Law, University of Toledo (1975-1978); Attorney, Emens, Hurd, Kegler & Ritter (1970-1975); African Fellow, Maxwell School, Syracuse University (1966-1969).