Bowlby, J. (1980) Attachment and Loss, vol. 3, New York, Basic Books.
Howes, C. and Matheson, C.C. (1992) ‘Sequences in the development of competent play with peers: social and social pretend play’, Developmental Psychology, vol. 28, no. 5, pp. 961–74.
Montgomery, H. (2008) An Introduction to Childhood: Anthropological Perspectives on Children’s Lives, Chichester, John Wiley and Sons.
Piaget, J. (1929) The Child’s Conception of the World, London, Routledge and Kegan Paul.
Rutter, M. (1981) Maternal Deprivation Reassessed, New York, NY, Penguin.
Vygotsky, L.S. (1962) Thought and Language, Cambridge, MA, Harvard University Press.