Hannaford, J. (1968). Student's guide to Heilbroner: The economic problem. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Hannaford, John. Student's Guide to Heilbroner: The Economic Problem. Englewood Cliffs, N.J: Prentice-Hall, 1968.
Lua MLA (9ú heag.)Hannaford, John. Student's Guide to Heilbroner: The Economic Problem. Prentice-Hall, 1968.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.