APA (7e ed.) Bronvermelding

Langford, P. (1987). Concept development in the primary school. Croom Helm.

Chicago (17e ed.) Bronvermelding

Langford, Peter. Concept Development in the Primary School. London ; New York: Croom Helm, 1987.

MLA (8e ed.) Bronvermelding

Langford, Peter. Concept Development in the Primary School. Croom Helm, 1987.