Barrett, J. (2007). Test your numerical aptitude: How to assess your numeracy skills and plan your career. Kogan Page.
Chicago-referens (17:e uppl.)Barrett, Jim. Test Your Numerical Aptitude: How to Assess Your Numeracy Skills and Plan Your Career. London: Kogan Page, 2007.
MLA-referens (9:e uppl.)Barrett, Jim. Test Your Numerical Aptitude: How to Assess Your Numeracy Skills and Plan Your Career. Kogan Page, 2007.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.