(2003). IELTS [international english language testing system]. British Council.
Chicagoスタイル(17版)引用形式IELTS [international English Language Testing System]. British Council, 2003.
MLA(8版)引用形式IELTS [international English Language Testing System]. British Council, 2003.
警告: この引用は必ずしも正確ではありません.