Harbury, C. (1982). Workbook in Introductory Economics (Third Edition). ELSEVIER.
Lua i Stíl Chicago (17ú heag.)Harbury, Colin. Workbook in Introductory Economics (Third Edition). ELSEVIER, 1982.
Lua MLA (8ú heag.)Harbury, Colin. Workbook in Introductory Economics (Third Edition). ELSEVIER, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.