1. Sampling Techniques;Cochran,1977
2. Sample weights for coverage: a stochastic interpretation;Cowan,1990
3. Compensating for missing data;Kalton,1983
4. Sampling rare and elusive populations;Sudman;Science,1988
5. Mall intercepts and clinical trials: the philosophy of inference from different types of research designs;Cowan;Marketing Res,1989