Ullmann, Walter,  1910-1983. <br/><br/>
Principles of government and politics in the Middle Ages/ 
Walter Ullmann. 
 - 3rd ed. 
 - London:  Methuen,  1974. 
 - 341 p., plate :  ill. ;   22 cm. 
<br/><br/>Includes index and bibliography: p. 13-14. 
<br/><br/><label>ISBN: </label>0064771954 
<br/><br/><label>Subjects--Topical Terms: </label><br/>State, The.<br/>Constitutional history, Medieval.