Blue Origin BE-4 Engine en-US. ციტატა: „We chose LNG because it is highly efficient, low cost and widely available. Unlike kerosene, LNG can be used to self-pressurize its tank. Known as autogenous repressurization, this eliminates the need for costly and complex systems that draw on Earth’s scarce helium reserves. LNG also possesses clean combustion characteristics even at low throttle, simplifying engine reuse compared to kerosene fuels.“ ციტირების თარიღი: 2019-06-14
Cornell, Clayton B. (April 29, 2008). „Natural Gas Cars: CNG Fuel Almost Free in Some Parts of the Country“. დაარქივებულია ორიგინალიდან — იანვარი 20, 2019. ციტირების თარიღი: ივლისი 9, 2019. ციტატა: „Compressed natural gas is touted as the 'cleanest burning' alternative fuel available, since the simplicity of the methane molecule reduces tailpipe emissions of different pollutants by 35 to 97%. Not quite as dramatic is the reduction in net greenhouse-gas emissions, which is about the same as corn-grain ethanol at about a 20% reduction over gasoline“
Cornell, Clayton B. (April 29, 2008). „Natural Gas Cars: CNG Fuel Almost Free in Some Parts of the Country“. დაარქივებულია ორიგინალიდან — იანვარი 20, 2019. ციტირების თარიღი: ივლისი 9, 2019. ციტატა: „Compressed natural gas is touted as the 'cleanest burning' alternative fuel available, since the simplicity of the methane molecule reduces tailpipe emissions of different pollutants by 35 to 97%. Not quite as dramatic is the reduction in net greenhouse-gas emissions, which is about the same as corn-grain ethanol at about a 20% reduction over gasoline“
