Definition of "source"

More than a mere source of Promethean sustenance to thwart the cold and cook one's meat, wood was quite simply mankind's first industrial and manufacturing fuel.

2006, Edwin Black, chapter 2, in Internal Combustion‎

Investors face a quandary. Cash offers a return of virtually zero in many developed countries; government-bond yields may have risen in recent weeks but they are still unattractive. Equities have suffered two big bear markets since 2000 and are wobbling again. It is hardly surprising that pension funds, insurers and endowments are searching for new sources of return.

2013 July 6, “The rise of smart beta”, in The Economist, volume 408, number 8843, page 68

Most of the Himalayan rivers have been relatively untouched by dams near their sources. Now the two great Asian powers, India and China, are rushing to harness them as they cut through some of the world's deepest valleys.

2013 August 16, John Vidal, “Dams endanger ecology of Himalayas”, in The Guardian Weekly, volume 189, number 10, page 8

But the point when it would have to look at alternative new-build vehicles was always looming large, and there would inevitably be a finite number of Class 66s it could source from elsewhere, and a limit to other locomotives it could re-power.

2023 July 12, Pip Dunn, “Class 99s: "ultimate Electro-Diesel"”, in RAIL, number 987, page 52