- Biogas (D) – Wikipedia
- Biogas (D) – Multitalent Biogas
- Biogas (D) – Grundlagen effizienter und effektiver Strömungserzeugung in Biogasanlagen
- Biogas und Biokohle (D) – Effizienzsteigerung in Biogasanlagen
- Biochar (Eng) – Effects on Soil Phosphorus Sorption and Release
- Biochar (Eng) – Leaching of organic carbon, nitrogen, and phosphorus from compost in bioretention systems
- Biogas (Eng) – Alternative energy source
- Biogas (Eng) – Biogas Technology for Poverty Reduction and Sustainable Development (Results International Seminar UNAPCAEM/United Nations Asian and Pacific Centre for Agricultural Engineering and Machinery)
- Biogas (Eng) – Improved Biogas Unit for Developing Countries
- Biogas (Eng) – From food waste / India (Film; 5:36 min.)
- Biogas (Eng) – Nepal: Benefit for women, their families and the climate (Video; 8:31 min.)
- Biogás (Esp) – Wikipedia
- Biogás (Esp) – Manual para usuari@s
- Biogás (Esp) – de los desechos orgánicos en Costa Rica (película 3:46)
- Biogaz (Fr) – Film d’animation sur le biogaz et la méthanisation (3:43 min.)