UNESCO. (1999). Adult learning and the challenges of the 21st century. UNESCO.
Chicago ZitierstilUNESCO. Adult Learning and the Challenges of the 21st Century. Germany: UNESCO, 1999.
MLA ZitierstilUNESCO. Adult Learning and the Challenges of the 21st Century. UNESCO, 1999.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.