Howarth RW, Santoro R, and Ingraffea A (2011). Methane and the greenhouse gas footprint of natural gas from shale formations. Climatic Change Letters, [2]Archyvuota kopija 2011-12-22 iš Wayback Machine projekto.
Howarth RW, Santoro R, and Ingraffea A (2011). Methane and the greenhouse gas footprint of natural gas from shale formations. Climatic Change Letters, [2]Archyvuota kopija 2011-12-22 iš Wayback Machine projekto.