1. Jank. Jensen: biogas and natural gas fuel mixture for the future (1st world conference and exhibition on biomass for energy and industry, SEVILLA 2000).
2. Min-Bae Kim, Youn-Sang Bae, Dae-Ki Choi, Chang-Ha Lee: Ind. Eng. Chem. Res. Vol 45(2006), p.5050.
3. Simone Cavenati, Carlos A. Grande and Alı´rio E. Rodrigues:Energy & Fuels. Vol 19(2005) , p.2545.
4. Carlos A. Grande, Alı´rio E. Rodrigues: Ind. Eng. Chem. Res. Vol 46(2007), p.4595.
5. Simone Cavenati, Carlos A. Grande and Alı´rio E. Rodrigues:Energy & Fuels. Vol 20(2006) , p.2648.