Johnston, E. G. (1930). Point systems and awards: The guidance, stimulation and limitation of pupil participation. A.S. Barnes and company, incorporated.
Lua i Stíl Chicago (17ú heag.)Johnston, Edgar Grant. Point Systems and Awards: The Guidance, Stimulation and Limitation of Pupil Participation. New York: A.S. Barnes and company, incorporated, 1930.
Lua MLA (9ú heag.)Johnston, Edgar Grant. Point Systems and Awards: The Guidance, Stimulation and Limitation of Pupil Participation. A.S. Barnes and company, incorporated, 1930.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.