Goddard, T., & Grattidge, A. (1969). Beta mathemtics 1-4. Schofield & Sims.
Lua i Stíl Chicago (17ú heag.)Goddard, T.T, agus A.W Grattidge. Beta Mathemtics 1-4. Huddersfield: Schofield & Sims, 1969.
Lua MLA (9ú heag.)Goddard, T.T, agus A.W Grattidge. Beta Mathemtics 1-4. Schofield & Sims, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.