@book{Groves2009,
author = {Groves, R.M. and Fowler Jr., F.J. and Couper, M.P. and Lepkowski, J.M. and Singer, E. and Tourangeau, R. },
title= {Survey methodology},
year = {2009},
address = {Hoboken, NJ},
publisher = {John Wiley and Sons},
}