1. Young children's thinking: Studies of some aspects of Piaget's theory;Almy,1966
2. Learning and operational convergence in logical thought development;Beilin;Journal of Experimental Child Psychology,1965
3. Structure and direction in thinking;Berlyne,1965
4. Piaget on reasoning: A methodological critique and alternative proposal;Braine,1962
5. Conservation of a shape property;Braine;Canadian Journal of Psychology,1965