UNESCO. (1999). Adult learning and the challenges of the 21st century. UNESCO.
シカゴスタイル引用形UNESCO. Adult Learning and the Challenges of the 21st Century. Germany: UNESCO, 1999.
MLA引用形式UNESCO. Adult Learning and the Challenges of the 21st Century. UNESCO, 1999.
警告: この引用は必ずしも正確ではありません.