Estêvão de Perm
Origem: Wikipédia, a enciclopédia livre.
- Ferguson, Charles. 1971. St. Stefan of Perm and applied linguistics. (Originally published in 1967, in To Honor Roman Jakobson, ed. by Morris Halle, pp. 643-653. The Hague: Mouton. Also reprinted in 1968 Language Problems of Developing Nations, ed. by Joshua Fishman, Charles Ferguson, and J. Das Gupta, pp. 27-35. New York Wiley and Sons.) Language Structure and Language Use: Essays by Charles Ferguson, ed. by Answar S. Dil, pp. 197-218. Stanford: Stanford University Press.
- Martin, Janet, Medieval Russia, 980-1584, (Cambridge, 1995), pp. 225-6
- Zenkovsky, Serge A. (ed.), Medieval Russia's Epics, Chronicles, and Tales, Revised Edition, (New York, 1974), pp. 259-62