ASHWORTH, A. (1996). Pre-contract Studies Development Economics, Tendering And Estimating Allan Ashworth. Addison-Wesley.
Chicago-viite (17. p.)ASHWORTH, A. Pre-contract Studies Development Economics, Tendering And Estimating Allan Ashworth. Addison-Wesley, 1996.
MLA-viite (8. p.)ASHWORTH, A. Pre-contract Studies Development Economics, Tendering And Estimating Allan Ashworth. Addison-Wesley, 1996.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.