Two videos of the GEK at the Denver Zoo:
http://www.youtube.com/watch?v=dXNLTgZ35d4
http://www.9news.com/news/local/article.aspx?storyid=116243
gasifier vehicle- tuk tuk:
http://www.denverpost.com/news/ci_20227777/motorized-rickshaw-shows-off-power-zoo-poo?IADID=Search-www.denverpost.com-www.denverpost.com