Launay, Jacques de. <br/><br/>
Histoire de la diplomatie secrète, 1789-1914. 

 - Lausanne :  Recontre,  1966. 
 - 408 p. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Europe--Politics and government--1789-1900.