Social contract: essays by Locke, Hume, and Rousseau /
with an introduction by Sir Ernest Barker 
. - London  : Oxford : New York : Oxford University Press,  1967 
. - xliv, 307 p.  21 cm. 
<br/> An essay concerning the true original, extent and end of civil government / John Locke  <br/>  Of the original contract / David Hume  <br/>  The social contract / Jean-Jacques Rousseau <br/>