Modell, M. E. (1988). A professional's guide to systems analysis. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Modell, Martin E. A Professional's Guide to Systems Analysis. New York: McGraw-Hill, 1988.
Lua MLA (9ú heag.)Modell, Martin E. A Professional's Guide to Systems Analysis. McGraw-Hill, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.