1. The paradox of intention: Assessing children’s metarepresentational understanding;Astington,2001
2. Autism and symbolic play;Baron-Cohen;British Journal of Developmental Psychology,1987
3. A theory of play and fantasy;Bateson,1955
4. From exploration to play: a cross-sectional study of infant free play behavior;Belsky;Developmental Psychology,1981
5. Thinking without words;Bermudez,2003