Willemyns, R. & Bister, H. (1989). On the classification of languages. In C. I. Moore & S. V. Wright (Eds.), Languages and their classifications: Current issues in linguistic theory, vol. 4 (pp. 541-564). Walter de Gruyter.

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Willemyns, R. & Bister, H. (1989). On the classification of languages. In: Moore, C. I. & Wright, S. V. (Eds.), Languages and their classifications: Current issues in linguistic theory, vol. 4. Walter de Gruyter, pp. 541-564.