European Association for Research and Development in Higher Education & Verreck, W. A. (1974). Methodological problems in research and development in higher education: Proceedings of the inaugural congress of the European Association for Research and Development in Higher Education, Rotterdam, December 3-5, 1973. Swets & Zeitlinger.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)European Association for Research and Development in Higher Education و W. A. Verreck. Methodological Problems in Research and Development in Higher Education: Proceedings of the Inaugural Congress of the European Association for Research and Development in Higher Education, Rotterdam, December 3-5, 1973. Amsterdam: Swets & Zeitlinger, 1974.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)European Association for Research and Development in Higher Education و W. A. Verreck. Methodological Problems in Research and Development in Higher Education: Proceedings of the Inaugural Congress of the European Association for Research and Development in Higher Education, Rotterdam, December 3-5, 1973. Swets & Zeitlinger, 1974.