1. Gass, Michael. 1992. Theory and practice. Journal of Experiential Education 15(2): 6–7.
2. Haig, Geoffrey. 1991. Universal Grammar and second language acquisition: the influence of task type on late learners’ access to the subjacency principle. TESL monograph, McGill University.
3. Hatch, Evelyn M., and Hossein Farhady. 1982. Research design and statistics for applied linguistics. Cambridge: Newbury House Publishers.
4. Hopp, Holger. 2007. Ultimate attainment at the interfaces in second language acquisition (Doctoral dissertation). Groningen University.
5. Jiang, Nan. 2004. Morphological insensitivity in second language processing. Applied Psycholinguistics 25(4): 603–634.