Bulletin #7216, Maine Home Energy: How Much Heat Per Dollar?
https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html
https://www.eia.gov/energyexplained/units-and-calculators/
https://www.extension.iastate.edu/agdm/wholefarm/html/c6-87.html
ttps://www.generatorjoe.net/html/energy.html
https://www.eia.gov/energyexplained/units-and-calculators