Gill, K., & Smith, D. L. (1986). International research centers directory 1986-1987: A World Guide to government, university, independent nonprofit, and commerical research and development centers, institutes, laboratories, bureaus, test facilities, experinent stations, and data collection and analysis centeers, as well as foundations, councils, and other organizations which support research (3rd ed.). Gale Research Co..
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Gill, Kay, و Darren L. Smith. International Research Centers Directory 1986-1987: A World Guide to Government, University, Independent Nonprofit, and Commerical Research and Development Centers, Institutes, Laboratories, Bureaus, Test Facilities, Experinent Stations, and Data Collection and Analysis Centeers, as Well as Foundations, Councils, and Other Organizations Which Support Research. 3rd ed. Detroit, Mich.: Gale Research Co., 1986.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)Gill, Kay, و Darren L. Smith. International Research Centers Directory 1986-1987: A World Guide to Government, University, Independent Nonprofit, and Commerical Research and Development Centers, Institutes, Laboratories, Bureaus, Test Facilities, Experinent Stations, and Data Collection and Analysis Centeers, as Well as Foundations, Councils, and Other Organizations Which Support Research. 3rd ed. Gale Research Co., 1986.