Spencer, M. H. (1986). Contemporary economics (6ª ed.). Worth.
Lua i Stíl Chicago (17ú heag.)Spencer, Milton H. Contemporary Economics. 6ª ed. Worth, 1986.
Lua MLA (9ú heag.)Spencer, Milton H. Contemporary Economics. 6ª ed. Worth, 1986.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.