1. Spontaneous play: An avenue for intellectual development;Almy,1968
2. Some functions of play in the education process;Arnaud;Childhood Education,1971
3. A child learns to write and read;Bissex,1980
4. Qualitative research for educators: An introduction to theory and method;Bogdan,1982
5. Developmental correlates of role-playing ability;Bower;Child Development,1975