Não informado. University of Iowa studies in character. Institute of Character Research.
Chicago-viite (17. p.)Não informado. University of Iowa Studies in Character. Iowa City, Iowa: Institute of Character Research.
MLA-viite (8. p.)Não informado. University of Iowa Studies in Character. Institute of Character Research.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.