DeWitt, N. (1961). Education and professional employment in the U.S.S.R. Prepared for the National Science Foundation by the Office of Scientific Personnel, National Academy of Sciences-National Research Council. National Science Foundation.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)DeWitt, Nicholas. Education and Professional Employment in the U.S.S.R. Prepared for the National Science Foundation by the Office of Scientific Personnel, National Academy of Sciences-National Research Council. [Washington]: National Science Foundation, 1961.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)DeWitt, Nicholas. Education and Professional Employment in the U.S.S.R. Prepared for the National Science Foundation by the Office of Scientific Personnel, National Academy of Sciences-National Research Council. National Science Foundation, 1961.