Ayres, L. P. (1909). Laggards in our schools: A study of retardation and elimination in city school systems. Charities publication committee.
Lua i Stíl Chicago (17ú heag.)Ayres, Leonard Porter. Laggards in Our Schools: A Study of Retardation and Elimination in City School Systems. New York: Charities publication committee, 1909.
Lua MLA (8ú heag.)Ayres, Leonard Porter. Laggards in Our Schools: A Study of Retardation and Elimination in City School Systems. Charities publication committee, 1909.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.