Wolf, C., Joye, D., Smith, T. W., & Fu, Y. The Sage handbook of survey methodology. Sage.
Dyfyniad Arddull ChicagoWolf, Christof, Dominique Joye, Tom W. Smith, and Yang-chih Fu. The Sage Handbook of Survey Methodology. London: Sage.
Dyfyniad MLAWolf, Christof, et al. The Sage Handbook of Survey Methodology. Sage.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.