@article{Igou2002,
author = {Igou, E. and Bless, H. and Schwarz, N.},
title= {Making sense of standardized survey questions: The influence of reference periods and their repetition},
year = {2002},
doi = {10.1080/714041712},
journal = {Communication Monographs},
volume = {69},
number = {2},
pages = {179−187},
}