APA (7th ed.) Citation

Van Ek, J., & Alexander, L. (1988). Threshold level english in a european unit/credit system for modern language learning by adults. Longman.

Chicago Style (17th ed.) Citation

Van Ek, J.A, and L.G Alexander. Threshold Level English in a European Unit/credit System for Modern Language Learning by Adults. London: Longman, 1988.

MLA (9th ed.) Citation

Van Ek, J.A, and L.G Alexander. Threshold Level English in a European Unit/credit System for Modern Language Learning by Adults. Longman, 1988.