Não informado. (1971). Educational documentation and information. International Bureau of Education.
Chicago-Zitierstil (17. Ausg.)Não informado. Educational Documentation and Information. Geneve, Suíça: International Bureau of Education, 1971.
MLA-Zitierstil (8. Ausg.)Não informado. Educational Documentation and Information. International Bureau of Education, 1971.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.