Henderson, A., Frost, D., Tergujeff, E., Kautzsch, A., Murphy, D., Kirkova-Naskova, A., Waniek-Klimczak, E., Levey, D., Cunnigham, U. and Curnick, L. (2012) “The English Pronunciation Teaching in Europe Survey: Selected Results”, Research in Language, 10(1), pp. 5–27. doi: 10.2478/v10015-011-0047-4.