LPG and CNG

[Eric Bruun]

For a good summary of the issues of alternative fuels, try 
the Transit Cooperative Research Program reports. I can't remember
which volume, but they are listed at the American Public Transportation
Association cite, www.apta.com. Then find the TCRP program and read
the titles. The report has further references. You may also order
one copy for free, although I do not know if APTA pays international
postage. I hope this helps. Eric Bruun