HELFERT ERICH A. (1992). TECHNIQUES OF FINANCIAL ANALYSIS. JAICO PUBLISHING HOUSE.
Lua i Stíl Chicago (17ú heag.)HELFERT ERICH A. TECHNIQUES OF FINANCIAL ANALYSIS. MUMAI: JAICO PUBLISHING HOUSE, 1992.
Lua MLA (9ú heag.)HELFERT ERICH A. TECHNIQUES OF FINANCIAL ANALYSIS. JAICO PUBLISHING HOUSE, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.