Modell, M. E. (1996). A professionals guide to systems analysis. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Modell, Martin E. A Professionals Guide to Systems Analysis. McGraw-Hill, 1996.
Lua MLA (8ú heag.)Modell, Martin E. A Professionals Guide to Systems Analysis. McGraw-Hill, 1996.
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