Hart, H. L. A. <br/><br/>
The Concept of law / 
H. L. A. Hart. 
 - 3rd  ed. 
 - Oxford :  O. U. P.,  2012. 
 - lv, 333 p. 
<br/><br/><label>ISBN: </label>0199644704 : 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Jurisprudence--Methodology.<br/>Law--Philosophy.