2Eiichi Taniguchi.Underground freight transport system as city logistics measures,2002.
3Dietrich Stein.Development of Capsule Pipelines and Tube Transportation Systems,2002.
4Henry Liu.Freight transport by Underground Pipelines:State-of-the-Art Assessment,2002.
5Johan Visser.Underground freight transport in urban area,1999.
6John Vissor.what is the optimum tube diameter?A difficult answer to a very simple question,2002.
7A.p. James;Ir.F.M.Sanders;Ir.G.Arends.Houston projects 2000 and 2001-research leading to the design of a palletized cargo consolidation and distribution ULS for Houston,2002.
