1. Mercator European Research Centre on Multilingualism and Language Learning, Fryske Akademy , Doelestraat 8, 8911 DX Leeuwarden , Netherlands
2. European Centre for Minority Issues , Schiffbrücke 12, 24939 Flensburg , Germany
3. Department of Psychological and Brain Sciences and Department of Linguistics, University of Iowa , 459 Phillips Hall, Iowa City, IA, 52242 , USA
4. Algemiene Fryske Underrjocht Kommisje (Afûk) , Boterhoek 3, 8911 DH Leeuwarden , Netherlands