Al Rutan's Methane Digesters

Found this free ebooks at http://www.green-trust.org  and I love it, my favorite digester yet:
Encontré estos libros electrónicos gratuitos en   http://www.green-trust.org  y me encanta, es mi digestor favorito hasta ahora:
Methane1-1.pdf
Methane1-2.pdf
Methane1-3.pdf
Methane1-4.pdf
Methane1-5.pdf
Methane1-6.pdf
Methane1-7.pdf
Al's 3 hour video on Methane production and Use