APA (7th ed.) Citation

Smil, V. (2015). Natural Gas: Fuel for the 21st Century. Wiley & Sons.

Chicago Style (17th ed.) Citation

Smil, Vaclav. Natural Gas: Fuel for the 21st Century. Oxford: Wiley & Sons, 2015.

MLA (9th ed.) Citation

Smil, Vaclav. Natural Gas: Fuel for the 21st Century. Wiley & Sons, 2015.

Warning: These citations may not always be 100% accurate.