Willard, J. A., Burghardt, L., Kohl, K., & Anders, Y. (2024). Does entering early childhood education as a toddler benefit language and social development until age seven? A propensity score analysis. Applied Developmental Science. Advance online publication. https://doi.org/10.1080/10888691.2024.2382122

Kohl, K., Bihler, L.-M., Agache, A., Leyendecker, B., & Willard, J. A. (2022). Do peers matter? Peer effects on young children’s vocabulary gains in German classrooms. Journal of Educational Psychology, 114(1), 161-176. https://doi.org/10.1037/edu0000522

Willard, J. A., Leyendecker, B., Kohl, K., Bihler, L.-M., & Agache, A. (2022). Does variation in early childhood education matter more for dual language learners’ than for monolingual children’s language development? Applied Developmental Science, 26(4), 704-725. https://doi.org/10.1080/10888691.2021.1978845

Willard, J. A., Agache, A., Kohl, K., Bihler, L.-M., & Leyendecker, B. (2021). Longitudinal interrelations between nonword repetition and vocabulary from age three to five: Evidence for within-child processes? Developmental Psychology, 57(9), 1423-1438. https://doi.org/10.1037/dev0001230

Willard, J. A., Kohl, K., Bihler, L.-M., Agache, A., & Leyendecker, B. (2021). Family literacy activities and their interplay with family and preschool language environments: Links to gains in dual language learners’ German vocabulary. Early Education and Development, 32(2), 189-208. https://doi.org/10.1080/10409289.2020.1744404

Kohl, K., Bihler, L.-M., Willard, J. A., Agache, A., & Leyendecker, B. (2019). Linking quantity and quality of early childhood education and care to children’s socio-emotional adjustment: A German cross-sectional study. Early Education and Development, 31(2), 177-199. https://doi.org/10.1080/10409289.2019.1650543

Kohl, K., Willard, J. A., Agache, A., Bihler, L.-M., & Leyendecker, B. (2019). Classroom quality, classroom composition, and age at entry: Experiences in early childhood education and care and single and dual language learners’ German vocabulary. AERA Open, 5(1), 1–16. https://doi.org/10.1177/2332858419832513

Willard, J. A., Agache, A., & Leyendecker, B. (2019). Classroom composition, classroom quality and German skills of very young dual language learners and German-only learners. Early Childhood Research Quarterly, 49(4), 269-281. https://doi.org/10.1016/j.ecresq.2019.07.004

Bihler, L.-M., Agache, A., Schneller, K., Willard, J. A., & Leyendecker, B. (2018). Expressive morphological skills of dual language learning and monolingual German children: Exploring links to duration of preschool attendance, classroom quality, and classroom composition. Frontiers in Psychology, 9, Article 888. https://doi.org/10.3389/fpsyg.2018.00888

Willard, J. A., Agache, A., Jäkel, J., Glück, C. W., & Leyendecker, B. (2015). Family factors predicting vocabulary in Turkish as a heritage language. Applied Psycholinguistics, 36(4), 875-898. https://doi.org/10.1017/S0142716413000544