Al-Sowygh, H. I. Z., & Bryant, H. (1981). Performance of a piagetian test by Saudi Arabian students in Colorado colleges and universities in relation to selected socio demographic and academic data. State University of New York at Buffalo.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Al-Sowygh, Hamad Ibn Zeid, و Howard Bryant. Performance of a Piagetian Test by Saudi Arabian Students in Colorado Colleges and Universities in Relation to Selected Socio Demographic and Academic Data. New York: State University of New York at Buffalo, 1981.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Al-Sowygh, Hamad Ibn Zeid, و Howard Bryant. Performance of a Piagetian Test by Saudi Arabian Students in Colorado Colleges and Universities in Relation to Selected Socio Demographic and Academic Data. State University of New York at Buffalo, 1981.