00289nam a2200121 a 450000500170000002000150001708200180003210000170005024500310006725000110009826000370010930000210014620251203091611.0  a0044457227  a300.723,bvau  aVaus, D.A.de  aSurveys in social research  a2nd ed  aLoNew Delhion: Unwin Hymanc1986  axiv, 343p.c22cm