Kuah, B. T. (1998). A study of the perception of secondary school principals and teachers in the district of Petaling, Selangor on the zero defects concept.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Kuah, Bee Tin. A Study of the Perception of Secondary School Principals and Teachers in the District of Petaling, Selangor on the Zero Defects Concept. 1998.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Kuah, Bee Tin. A Study of the Perception of Secondary School Principals and Teachers in the District of Petaling, Selangor on the Zero Defects Concept. 1998.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.