Não informado. University of Iowa studies in character. Institute of Character Research.
Citação do estilo Chicago (17ª ed.)Não informado. University of Iowa Studies in Character. Iowa City, Iowa: Institute of Character Research.
Citação MLA (8ª ed.)Não informado. University of Iowa Studies in Character. Institute of Character Research.
Atenció: Aquestes cites poden no estar 100% correctes.