General Certificate of Secondary Education. (1990). Co-ordinated science: The Suffolk development. East Midland Regional Examination Board.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)General Certificate of Secondary Education. Co-ordinated Science: The Suffolk Development. [s.l.]: East Midland Regional Examination Board, 1990.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)General Certificate of Secondary Education. Co-ordinated Science: The Suffolk Development. East Midland Regional Examination Board, 1990.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.