lester, a. (1982). project planning and control. butterworth & co publishers Ltd.
Lua i Stíl Chicago (17ú heag.)lester, albert. Project Planning and Control. london: butterworth & co publishers Ltd, 1982.
Lua MLA (9ú heag.)lester, albert. Project Planning and Control. butterworth & co publishers Ltd, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.