Barrett, J. (2007). Test your numerical aptitude: How to assess your numeracy skills and plan your career. Kogan Page.
Lua i Stíl Chicago (17ú heag.)Barrett, Jim. Test Your Numerical Aptitude: How to Assess Your Numeracy Skills and Plan Your Career. London: Kogan Page, 2007.
Lua MLA (9ú heag.)Barrett, Jim. Test Your Numerical Aptitude: How to Assess Your Numeracy Skills and Plan Your Career. Kogan Page, 2007.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.