APA (7 वां संस्करण) प्रशस्ति पत्र

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

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

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

एमएलए (9वां संस्करण) प्रशस्ति पत्र

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