@inbook{Sturgis2009,
author = {Sturgis, P. and Allum, N. and Brunton-Smith, I.},
title= {Attitudes over time: The psychology of panel conditioning},
year = {2009},
doi = {10.1002/9780470743874.ch7},
editor = {Lynn, P.},
booktitle = {Methodology of longitudinal surveys},
address = {Chichester},
publisher = {Wiley},
pages = {113--126},
}