Duffy, K. G. (1998). Annual Editions: Psychology. 1998/99. Dushkin/McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Duffy, Karen G. Annual Editions: Psychology. 1998/99. Guilford: Dushkin/McGraw-Hill, 1998.
Lua MLA (9ú heag.)Duffy, Karen G. Annual Editions: Psychology. 1998/99. Dushkin/McGraw-Hill, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.