Zhou, Ying. “Development over Time in Cognitive Function Among European 55-69-Year-Olds from 2006 to 2015, and Differences of Region, Gender, and Education”. Comparative Population Studies 47 (March 29, 2022). Accessed May 19, 2024. https://comparativepopulationstudies.de/index.php/CPoS/article/view/330.