平台:
ProQuest Political Science Database
(Available from 1998/01/01 until 1998/12/31. Available from 2000/01/01 until 2006/12/31. Available from 2008/01/01.)
ProQuest Political Science Database
(Available from 1998/01/01 until 1998/12/31. Available from 2000/01/01 until 2006/12/31. Available from 2008/01/01.)