Bilbrough, N. 2007. Dialogue Activities to Exploring Spoken Interaction in the Language Class. Cambridge: Cambridge University Press
Brown, H.D., Gillian and Yule, George. 1999. Teaching the spoken Language. Cambridge University Press
Brown, H.D. 2000. Principles of Language Learning and Teaching (4th Edition). New York: Longman 
Brown, H. D. 2001. Teaching by Principles: An Interactive approach to Language Pedagogy. New York: Logman
Borg, W.R. 1981. Applying Educational Research. New York: Longman
Collie, J & Stephen.S. 2006. Speaking Student’s Book. Cambridge: Cambridge University Press
Hakim, M.A.R., 2015. Experienced EFL teachers’ challenges and strategies in teaching speaking for introvert students. European Journal of Social Sciences, 48(4). 437-446
Hakim, M.A.R., 2018. A Research and Development Study to EFL Learners: Designing A Speaking Module For Introvert Students Based on Cooperative Learning. International Journal of English and Education, 7(2), 1-17
Hakim, M.A.R., Asiyah, A. and Syafri, F., 2018. Pengembangan Materi Ajar Animasi Bahasa Inggris Bagi Siswa Usia Dini di Raudhatul Aftal Kota Bengkulu. AWLADY: Jurnal Pendidikan Anak, 4(1), pp.30-49
Harmer, J. 1998. How to Teach English: an introduction to the practice of English language teaching. New York: Logman
Huda, M. 2013. Cooperative Learning. Yogyakarta: Pustaka Pelajar
Isjoni. 2012. Cooperative Learning: Efektivitas Pembelajaran Kelompok. Bandung: Alfabeta
Kardimin. 2013. English For Islamic Studies. Yogyakarta: Pustaka Pelajar
Latief, M.A. 2012. Research Method on Language Learning: An Introduction. Malang: UM Press
Mihalicek. V., & Christin. W. 2011. Language Files : Materials for an Introduction to Language and Linguistics. Ohio: Ohio State University
Miller, J., & Weinert, R. 1998. Spontaneous Spoken Language. New York: Clarendon Press Oxford 
Mustofa, M. 2012. The Journey of Professional Teachers. Language- Edu : Journal of English Teaching and Learning, 1 (1): 1-9.
Olson, M. H. & B.R, Horgenhahn. 2011. Teori-teori Kepribadian. Terjemahan oleh Yudi Santoro. 2013. Yogyakarta: Pustaka Pelajar
Peng, C.F and Zahari, I. 2008. Tahap Penggunaan Bahasa Melayu dan Bahasa Inggeris Dalam Kalangan Mahasiswa/i IPTA dan IPTS Dalam Sistem Pendidikan Negara. Jurnal Pengajian Melayu. 19: 16-36
Revola,Y. 2012. An Analysis of Students’ Problem in Speaking Unpublished thesis. Bengkulu: Fakultas Tarbiyah IAIN Bengkulu.
Santrock, J.W. 2014. Educational Psychology. New York: McGraw Hill
Sismiati, & Mohammad, A. L. 2012. Developing Instructional Materials On English Oral Communication for Nursing Schools. TEFLIN Journal, 2(23): 44-59.
Sunartyo,N. 2008. Kupas Tuntas Psikotes. Jogjakarta: Diva Press
Suprijono, A. 2013. Cooperative Learning: Teori & Aplikasi PAIKEM. Yokyakarta: Pustaka Pelajar
Tomlinson, B. 2002. Developing Materials for Language Teaching: London: Continuum
Wahid, Z.A.A. 2001. Bahasa Pendidikan dan Pembangunan. Kuala Lumpur: Dewan Bahasa dan Pustaka