HELFERT ERICH A. (1977). TECHNIQUES OF FINANCIAL ANALYSIS (4TH.). RICHARD D.IRWIN INC.
Lua i Stíl Chicago (17ú heag.)HELFERT ERICH A. TECHNIQUES OF FINANCIAL ANALYSIS. 4TH. ONTARIO: RICHARD D.IRWIN INC, 1977.
Lua MLA (9ú heag.)HELFERT ERICH A. TECHNIQUES OF FINANCIAL ANALYSIS. 4TH. RICHARD D.IRWIN INC, 1977.
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