1. Aspy, D. N. (1972). Toward a technology for humanizing education. Champaign, Illinois: Research Press Company.
2. Barrett-Lennard, G. T. (1998). Carl Rogers’ helping system: Journey and substance. London: Sage Publications.
3. Barrett-Lennard, G. T. (2005). Relationship at the centre: Healing in a troubled world. Philadelphia, PA: Whurr Publishers.
4. Cavalcante, F. (2009). Projeto CASa. Austria: Presentation at the University of Vienna.
5. Cornelius-White, J. H. (2007). Learner-centered teacher-student relationships are effective: A meta-analysis. Review of Educational Research,
77, 113–143.