F. Demie / A. Hau / J. McDonald, Language Diversity and Attainment in Primary Schools, 2015, p. 16 ([Internet, 2020-07-29](https://www.lambeth.gov.uk/rsu/sites/www.lambeth.gov.uk.rsu/files/Language_Diversity_and_Attainment_in_Primary_Schools_2012.pdf))