?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.aulast=Lawton&rft.aufirst=Denis&rft.au=Lawton%2C+Denis&rft.degree=Doctoral&rft.tpages=385&rft.title=A+study+of+linguistic+differences+in+samples+of+the+speech+and+writing+of+groups+of+working-class+and+middle-class+boys+aged+twelve+and+fifteen&rft.inst=Institute+of+Education%2C+University+of+London&rft.date=1966