4Jessner, U. Metalinguistic awareness in multilingual: Cognitive aspects of third language learning [ J ]. Lan- guage Awareness, 1999 (3), 201 - 209.
5Cenoz, J. Hufeisen, B. & Jesssner, U. Cross - linguis- tic Influence in Third Language Acquisition: Psychologi- cal Perspectives [ C ]. Clevedon: Multilingual Matters Ltd, 2001.
6Hcrdina, P. & Jessner, U. The dynamics of third lan- guage acquisition [ A ]. in Cenoz, J. & Jessner, U. (eds). English in Europe: The Acquisition of a Third Language[ C]. Clevedon: Multilingual Matters, 2000.
7Jorda, M. P. S. Third Language Learners- Pragmatic Production and Awareness [ M ]. Clevedon: Multilingual Matters Ltd, 2005.
8De Anglis, G. & Selinker, L. Interlanguage transfer and competing language system [ A ]. in Cenoz, J. Hufeis- en, B. &U. Jessner(eds). Cross-Linguistic Influence in Third Language Acquisition: Psycholinguistic Per- spective[ C]. Clevedon: Multilingual Matters, 2001.
9Thomas, J. The role played by metalinguistic awareness in second and third language learning [ J ]. Journal of Multilingual and Multicultural Development, 1988 (9), 235 - 246.
10Williams, S. and Hammarberg, B. Language switches in L3 production: Implications for a polyglot speaking model [ J ].Applied Linguistics, 1998 ( 19 ), 295 - 333.
