Sully. Etudes sur l'enfance

2. Lukens. Astudy of children's drawings. Pedag. Seminary, v. IV, p. 79.

3. Pappenheim. Bemerkungen iiber Kinderzeichnungen. Zeitschr. f. pâd. Psych., Bd I.

4. O'Shea. Children's expression through drawing. Educat. Review, New-York, 1895. Du même. Some aspects of drawings. Ibid., 1897.

5. Brown. Notes on children's drawings. Univ. of Californie, Studies, 1887, v. I.