4[2]Shell International Petroleum Company Lim-ited.Fuels Development and Application-Motor Gaso-line (alternative fuels).Shell Centre,London,1976.
5[3]Menrad H,Wegener R,Loeck H.SAE Technical Paper Series No 852071,1985.
6[4]Hollemans B,Ban Der Weide J.Proceedings of the Symposium on the Use of CNG,LNG,LPG as Fuel for Internal Combustion Engines 23-27 Sep 1991,Kiev,Ukraine,
7[5]Hollemans B,Van Sloten P.Perspective of the automotive LPG market in Europe in 1995.TNO Road Vehicles Research Insti-tute,Delft,The Netherlands.
8[6]Pitstick M E.Preprint Paper No 930527,Transportation Research Board 72nd Annual Meetinig,10-14 Jan 1993,Washington DC,USA.
