National Science Foundation (U.S.). (1969). Scientific technical and health personnel in the federal government 1969. U.S. Government Printing Office.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)National Science Foundation (U.S.). Scientific Technical and Health Personnel in the Federal Government 1969. Washington, D.C: U.S. Government Printing Office, 1969.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)National Science Foundation (U.S.). Scientific Technical and Health Personnel in the Federal Government 1969. U.S. Government Printing Office, 1969.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.