Siertsema, B. A test in phonetics: 500 questions andanswers on english pronunciation and how to teach it in west africa. Martinus Nijhoff.
Citazione stile Chigago Style (17a edizione)Siertsema, B. A Test in Phonetics: 500 Questions Andanswers on English Pronunciation and How to Teach It in West Africa. The Hague: Martinus Nijhoff.
Citatione MLA (9a ed.)Siertsema, B. A Test in Phonetics: 500 Questions Andanswers on English Pronunciation and How to Teach It in West Africa. Martinus Nijhoff.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.