Não informado. (2000). University of Iowa studies in social science. University of Iowa.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. University of Iowa Studies in Social Science. Iowa City, Iowa: University of Iowa, 2000.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. University of Iowa Studies in Social Science. University of Iowa, 2000.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.