- ‘The Anglo-Saxon runes of the 7th century. An essay on the runes of the Kentish area’, in: Futhark: International journal of Runic studies 1 (2010), pp. 18-50.
- ‘“Frisians” in England 400-1200AD’, in: The annals of the eleventh Friesian-Saxon symposium, 2009, ed. by N. E. Geertsema, Fryske Akademy, Ljouwert 2011, pp. 195-219.
- ‘Old Saxon - Frisian - English: Aspects of an Early Medieval North Sea Triangle’, in: Early Medieval Europe, vol. 15 (2007), pp. 211–237.
- ‘The Old Saxon Language’, in: The Germanic Languages, Routledge Language Family Descriptions, ed. by E. F. Konrad Koerner, Routledge, London, New York 2009, pp. 139–166.
- ‘The Old Frisian language’, in: The Germanic Languages, Routledge Language Family Descriptions, ed. by E. F. Konrad Koerner, Routledge, London, New York 2009, pp. 205–229.
Books
- ‘Linguistics of the Netherlands Antilles and Aruba - A Comprehensive Bibliography of Studies in English and Papiamentu’, Martinus Nijhoff Publishers, Leiden 1994.
- ‘Latin and the vernacular languages in the Netherlands 700-1350’, Brill Academic Publications, Leiden 2002.