- 1977Senior Staff Fellow
- 1986[position unknown]
- 1977Visiting Associate
- 1985[position unknown]
- 2004[position unknown]
- 2005[position unknown]
- 2006[position unknown]
- 2010[position unknown]
- 2012[position unknown]
- 1990[position unknown]
- 1991[position unknown]
- 1977Staff Fellow
- 1978Staff Fellow
- 2002[position unknown]
- 1991[position unknown]