Local
   
National & Public Libraries of Malta: http://opac.library.gov.mt/
University of Malta Library: http://www.um.edu.mt/library/

International 
 
Artnet: https://www.artnet.com/SERVICES/login.aspx
IIC: http://www.iiconservation.org/
HALI: http://www.hali.com/Logon.aspx
Library of Congress: http://catalog.loc.gov/
Smithsonian Institution: http://siris-libraries.si.edu/ipac20/ipac.jsp?
session=12A0B4K546929.55706&profile=liball&menu=search&submenu=subtab114&ts
=1220346547426#focus
University College London: http://library.ucl.ac.uk/F