Name	Info	Provider	Link
Full text from	free resource	CORE	https://core.ac.uk/reader/145643480?utm_source=linkout
Full text from	free resource	Enlighten: Publications, University of Glasgow	https://eprints.gla.ac.uk/154847
	subscription/membership/fee required	Silverchair Information Systems	https://pubs.aip.org/aip/rsi/article-lookup/doi/10.1063/1.4907935