RT Article T1 Theory and Practice of Sample Surveys JF Trends and perspectives in empirical social research SP 125 OP 139 A1 Stenger, Horst 1935- A1 Gabler, Siegfried 1951- LA English YR 1994 UL https://krimdok.uni-tuebingen.de/Record/1525884883 SN 3110143127 K1 Bevölkerungsumfrage K1 Samples K1 Methoden