Ek, J. A. v. (1975). The threshold level in a European unit / credit system for modern language learning by adults: Systems development in adult language learning. Council of Europe.
Chicago-Zitierstil (17. Ausg.)Ek, Jan Ate van. The Threshold Level in a European Unit / Credit System for Modern Language Learning by Adults: Systems Development in Adult Language Learning. Strasbourg: Council of Europe, 1975.
MLA-Zitierstil (9. Ausg.)Ek, Jan Ate van. The Threshold Level in a European Unit / Credit System for Modern Language Learning by Adults: Systems Development in Adult Language Learning. Council of Europe, 1975.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.