FORSTER, K.I. (1976). Levels of processing and the structure of the language processor. In R.J. Wales and E. Walker (eds.). New approaches to language mechanisms.Amsterdam: North-Holland Pub. Co.
2.
GARRETT, M.F. (1980). Levels of processing in sentence production. In B. Butterworth (ed.). Language production (Vol. 1, pp. 177–220). New York: Academic Press.
3.
KIMBALL, J. (1973). Seven principles of surface structure parsing in natural language. Cognition, 2, 15–47.
4.
TYLER, L.K. (1992). Spoken language comprehension.London: Lawrence Erlbaum.