the book and CD The Sounds of the IPA, Lingvistikaj Aspektoj de Esperanto, and the Longman Pronunciation Dictionary. He is the author of the most widely used English-Esperanto dictionary.

Until his retirement, Wells directed a two-week summer course in phonetics for University College London, focusing on practical and theoretical phonetics, as well as aspects of teaching phonetics. The course ends with written and oral examinations,