APA (7th ed.) Citation

Trim, J. L. M. (1980). Systems development in adult language learning: A European unit credit system for modern language learning by adults. Pergamon press.

Chicago Style (17th ed.) Citation

Trim, J. L. M. Systems Development in Adult Language Learning: A European Unit Credit System for Modern Language Learning by Adults. Oxford [etc.]: Pergamon press, 1980.

MLA (9th ed.) Citation

Trim, J. L. M. Systems Development in Adult Language Learning: A European Unit Credit System for Modern Language Learning by Adults. Pergamon press, 1980.