When, and how much, might effect estimates be biased when analysing mixed mode survey data? The roles of mode effects, mode selection, and mode split
Labour market status and well-being during the great recession: a changing relationship? -PhD thesis-
What happens if you offer a mobile option to your web panel? Evidence From a probability-based panel of Internet users
Evaluating relative mode effects in mixed-mode surveys: three methods to disentangle selection and measurement effects