Crawford, C. C., & Rogers, L. R. (1930). Studying the major subjects. C. C. Crawford.
Lua i Stíl Chicago (17ú heag.)Crawford, Claude C., agus Lester R. Rogers. Studying the Major Subjects. Los Angeles, Calif: C. C. Crawford, 1930.
Lua MLA (9ú heag.)Crawford, Claude C., agus Lester R. Rogers. Studying the Major Subjects. C. C. Crawford, 1930.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.