APA (7e ed.) Bronvermelding

Barr, H. (1966). Probation research: A survey of group work in the prbation service. H.M.S.O.

Chicago (17e ed.) Bronvermelding

Barr, Hugh. Probation Research: A Survey of Group Work in the Prbation Service. London: H.M.S.O, 1966.

MLA (9e ed.) Bronvermelding

Barr, Hugh. Probation Research: A Survey of Group Work in the Prbation Service. H.M.S.O, 1966.