Research reports. social studies. (2003) : Volume XXXI.

Eitemau Tebyg

• Research reports. (2003) : economic studies, Volume XIX.
• Research reports. (2003) : economic studies, Volume XX.
• Research reports social studies. Volume XI.
  Cyhoeddwyd: (1994)
• Research reports Social studies. Volume VIII.
  Cyhoeddwyd: (1993)
• Research reports social studies. Volume XII.
  Cyhoeddwyd: (1995)