4 links
Modern History Sourcebook | The Iron Law of Wages
fordham.edu
A selection from Ricardo's book, On Wages, describing the labor theory of value.
Ricardo on value: the three chapter ones
economics.soton.ac.uk
All three versions of the heavily revised first chapter of the book: On Value. From 1817, 1819 and 1821.
The Theory of Comparative Advantage
systemics.com
A highlight on Ricardo's lasting contribution, as well as a biography/bibliography.