APA (7th ed.) Citation

Stein, G. (1999). Exemplification in EFL dictionaries. The perfect learners' dictionary (?).

Chicago Style (17th ed.) Citation

Stein, Gabriele. "Exemplification in EFL Dictionaries." The Perfect Learners' Dictionary (?) 1999.

MLA (9th ed.) Citation

Stein, Gabriele. "Exemplification in EFL Dictionaries." The Perfect Learners' Dictionary (?), 1999.

Warning: These citations may not always be 100% accurate.