APA

τρυφωνοπουλος σ. Ι., . (1973). Attitudes toward formal and adult education. Athens: National Centre of Social Research.

Chicago

τρυφωνοπουλος σπύρος Ι, . 1973. Attitudes toward formal and adult education. Athens: National Centre of Social Research.

Harvard

τρυφωνοπουλος σ. Ι., . (1973). Attitudes toward formal and adult education. Athens: National Centre of Social Research.

MLA

τρυφωνοπουλος σπύρος Ι, . Attitudes toward formal and adult education. Athens: National Centre of Social Research. 1973.