1. “The description of linguistic variation in English: From Firth till the present day”;Aarts;English Studies,1976
2. “Toward a new perspective in Negro English dialectology”;Bailey;American Speech,1965
3. “Inherent variability and variable rules”;Bickerton;Foundations of Language,1971
4. “Subject concord of Be in Early Black English”;Brewer;American Speech,1973
5. Burgschmidt, E. and D. Götz. 1974. Kontrastive Linguistik: Deutsch/Englisch. Hueber Hochschulreihe 23.