SCOTT PEARL. (1999). EXERCISES IN MENTAL ARITHMETIC.
Lua i Stíl Chicago (17ú heag.)SCOTT PEARL. EXERCISES IN MENTAL ARITHMETIC. 1999.
Lua MLA (9ú heag.)SCOTT PEARL. EXERCISES IN MENTAL ARITHMETIC. 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.