http://www.kunsthaus.ch/en/library/digital-library/catalogues-raisonnes-and-critical-editions/?redirect_url=title%3DCommunique%C3%A9s%20%20%2F%2F%2Fcomponents%2Fcom_virtuemart%2Fshow_image_in_imgtag.php

Kunsthaus Zürich

Catalogues Raisonnés and Critical Editions

Gogh, Vincent van

Vincent van Gogh: The letters

The Vincent van Gogh Gallery

Goya y Lucientes, Francisco José ¬de¬

Info Goya

Nussbaum, Felix

Felix Nussbaum Werkverzeichnis

Picasso, Pablo

Online Picasso Project

Whistler, James McNeill

The correspondance of James McNeill Whistler