History of the Romani language
- Romani: A linguistic introduction. Cambridge: Cambridge University Press. (chapters 3-4).
- What is the Romani language? Hatfield: University of Hertfordshire Press.
, et al. 2000.
. 1926 [reprint. 1968]. The dialect of the Gypsies of Wales, being the older form of British Romani preserved in the speech of the clan of Abram Wood. Oxford: Clarendon Press.
1926. The position of Romani in Indo-Aryan. Journal of the Gypsy Lore Society, third series, 5: 145-189.
1988. The development of Romani linguistics. In: Jazayery, Mohammad Ali, and Winter, Werner. eds. Languages and cultures. Studies in honor of Edgar C. Polomé. Berlin: Mouton der Gruyter. 183-223.