3[6]Eran Friedler,Ehud Pisanty.Effects of design flow and treatment level on construction and operation costs of municipal wastewater treatment plants and their implications on policy making.Water Research.2006.
4[7]James Odeck.Cost overruns in road construction-what are their sizes and determinants.Transport Policy 11.2004.
5[8]Franco K.T.Cheung,Martin Skitmore.Application of cross validation techniques for modelling construction costs during the very early design stage.Building and Environment.2006.