The Mises Institute provides (totally legal) free downloads of digital copies of Carl Menger’s book On the Origins of Money here.
Carl Menger was the founder of the Austrian school of economics.
About the book:
“Written in the same year that he testified before the Currency Commission in Austria-Hungary, and published in English in 1892, Carl Menger explains that it is not government edicts that create money but instead the marketplace. Individuals decide what the most marketable good is for use as a medium of exchange. “Man himself is the beginning and the end of every economy,” Menger wrote, and so it is with deciding what is to be traded as money.”
About the Mises Institute:
“The Mises Institute, founded in 1982, teaches the scholarship of Austrian economics, freedom, and peace. The liberal intellectual tradition of Ludwig von Mises (1881-1973) and Murray N. Rothbard (1926-1995) guides us. Accordingly, we seek a profound and radical shift in the intellectual climate: away from statism and toward a private property order. We encourage critical historical research, and stand against political correctness. The Institute serves students, academics, business leaders, and anyone seeking better understanding of the Austrian school of economics and libertarian political theory.”
Find the download link of the book here.