@inbook{a62c5b4fb42e4d98af2ae5cfaf03777c,
title = "Validity issues in longitudinal research",
keywords = "validity, longitudinal research, attrition, measurement invariance, cross-sectional studies, density of measurements",
author = "{van den Bergh}, H.H. and J. Evers-Vermeul",
year = "2017",
language = "English",
series = "Studies on Language Acquisition (SOLA)",
publisher = "De Gruyter Mouton",
pages = "97--114",
editor = "J. Evers-Vermeul and E. Tribushinina",
booktitle = "Usage-based approaches to language acquisition and language teaching",
address = "Germany",
}