CLELAND DAVID I. (1984). SYSTEMS ANALYSIS & PROJECT MANAGEMENT (3RD.). MCGRAW-HILL.
Lua i Stíl Chicago (17ú heag.)CLELAND DAVID I. SYSTEMS ANALYSIS & PROJECT MANAGEMENT. 3RD. LONDON: MCGRAW-HILL, 1984.
Lua MLA (9ú heag.)CLELAND DAVID I. SYSTEMS ANALYSIS & PROJECT MANAGEMENT. 3RD. MCGRAW-HILL, 1984.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.