(1997). Engineering Economy E. Paul Degarmo [et Al.]. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Engineering Economy E. Paul Degarmo [et Al.]. Prentice-Hall, 1997.
Lua MLA (8ú heag.)Engineering Economy E. Paul Degarmo [et Al.]. Prentice-Hall, 1997.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.