Center for Applied Linguistics. (2005a). BEST Plus technical report. Washington, DC: Center for Applied Linguistics.
2.
Center for Applied Linguistics. (2005b). BEST Plus trainer manual. Washington, DC: Center for Applied Linguistics.
3.
Center for Applied Linguistics. (2007, December). Effects of instructional hours and intensity of instruction on NRS level gain in listening and speaking. Washington, DC: CAL Digest.
4.
Fulcher, G. (2003). Testing second language speaking. London: Pearson Education.
5.
Luoma, S. (2004). Assessing speaking. Cambridge : Cambridge University Press.
6.
National Reporting Service. (2008). Characteristics of English literacy participants in adult education: 2000-200 . Retrieved 14 August 2008, from http://www.nrsweb.org/reports/fast_facts.aspx
7.
van Lier, L. (1989). Reeling, writhing, drawling, stretching and fainting in coils: Oral proficiency interviews as conversation. TESOL Quarterly, 23, 489-508.