History. 

 - Londres-ENK :   International Institute for Conservation,   1975. 
 - páginas 40-45 
 - Irregular 
 - Vol. 12, no. 2(Win.1975) 
 - Art and archaeology technical abstracts   ;   Vol. 12, no. 2 .
<br/><br/> General methods and techniques. 
<br/><br/><br/>Inglés.