00295nam a2200097Ia 4500008004100000082001500041100002500056245006500081260004300146300000800189140113s9999    xx            000 0 und d  a574.4   L0  a"Clapham, A.R., Ed."  aThe IBP survey of conversation sites : an experimental study  a1980bCambridge Univ. PresscCambridge  a344