Duffy, K. G. (1998). Psychology 98/99 (28th ed.). Dushkin/McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Duffy, Karen G. Psychology 98/99. 28th ed. Guilford: Dushkin/McGraw-Hill, 1998.
Lua MLA (8ú heag.)Duffy, Karen G. Psychology 98/99. 28th ed. Dushkin/McGraw-Hill, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.