5Cenoz,J. Research on Mulfilingual Acquisition[ A]. In J. Cenoz & U. Jessner( eds. ) English in Europe: The Acquisition of a Third language [ C J. Clevedon: Multilingual Matters,2000.
6Cenoz,J. The Effect of Linguistic Distance,L2 Status and Age on Cross-linguistic Influence in Third Language Acquisition[ A]. In J. Cenoz. B. Hufeisen. & U. Jesssner. Cross-linguistic Influence in Third Language Acquisition :Psychological Perspectives [ C ]. Clevedon : Multilingual Matters Ltd ,2001.
7Cenoz, J. , Hufeisen, B. & Jesssner, U. Cross-linguistic Influence in Third Language Acquisition : Psychological Perspectives [ C ]. Clevedon: Multilingual Matters Lid, 2001.
8Cenoz, J. The Additive Effect of Bilingualism in Third Language Acquisition: A Review [ J ]. International Journal of Bilinguaiism, 2003(7).
9De Anglis, G. Third or Additional Language Acquisition [ M ]. Toronto : Multilingual Matters Ltd,2007.
10Ellis, R. The Study of Second Language Acquisition [ M ]. Oxford : Oxford University Press, 1994.