Siti Martini Mustapha. (2004). A qualitative analysis of teachers' questions and feedbacks: The differences between optionist and non-optionist English language teachers. Fakulti Sains Sosial dan Kemanusiaan, Universiti Kebangsaan Malaysia.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Siti Martini Mustapha. A Qualitative Analysis of Teachers' Questions and Feedbacks: The Differences Between Optionist and Non-optionist English Language Teachers. Bangi: Fakulti Sains Sosial dan Kemanusiaan, Universiti Kebangsaan Malaysia, 2004.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Siti Martini Mustapha. A Qualitative Analysis of Teachers' Questions and Feedbacks: The Differences Between Optionist and Non-optionist English Language Teachers. Fakulti Sains Sosial dan Kemanusiaan, Universiti Kebangsaan Malaysia, 2004.