Book Reviews : Community Action and Race Relations: A Study of Community Relations Committees in Britain. By MICHAEL J. HILL and RUTH M. ISSACHAROFF (London, Oxford University Press for the Institute of Race Relations, 1971). xvi + 295 pp., £4.25. The Prevention of Racial Discrimination in Britain. Edited by SIMON ABBOTT (London, Oxford University Press for the Institute of Race Relations, 1971). xviii + 453 pp., £5.00