Pigues D Keith. (2010). Winning with Customers. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)Pigues D Keith. Winning with Customers. New Jersey: John Wiley and Sons, 2010.
Lua MLA (9ú heag.)Pigues D Keith. Winning with Customers. John Wiley and Sons, 2010.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.