Traders and importers now use the term, as well as academic journals for example ACS publications (See 2006 article on comparing Petrodiesel emissions with other types of fuel). The term is common in blogs and informal wiki sites, and is used several times in this article itself.
L. D. Danny Harvey, 2010, "Energy and the New Reality 1: Energy Efficiency and the Demand for Energy Services," London:Routledge-Earthscan, ISBN 1844079120, p. 264, 267; see [2], accessed 28 September 2014.
Duffy, Michael C. (1 Ιανουαρίου 2003). Electric Railways 1880-1990. London: Institution of Engineering and Technology. ISBN0852968051. Ανακτήθηκε στις 9 Οκτωβρίου 2014.