1. US  DoE (Department of Energy) Energy 101 videos : Biofuels – Algae to fuel (Sept. 2012) – Text version available
NREL (National Renewable Energy Laboratory, US DoE) : Biofuel basics  – Text version available

2. Euronews, 13 May 2008 : Waste not, want not (biogas production in Vasteras, Sweden)
Listen (Transcript here)