National Book Development Council of Singapore. (1981). First national readership survey. National Book Development Council of Singapore.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Book Development Council of Singapore. First National Readership Survey. [Singapore]: National Book Development Council of Singapore, 1981.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)National Book Development Council of Singapore. First National Readership Survey. National Book Development Council of Singapore, 1981.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.