Master Drawings London is a coordinated sale of master drawings by a number of galleries in London, UK, from 27 June to 5 July, 2012.
This is apparently the 12th such sale, and the event has a dedicated website from which you can access an online catalog. Though it unfortunately takes the form of one of those cutesy page-flipping online magazines, you can zoom in on the images and, if you click the “Menu” button at upper left, you can download a PDF version.
“Drawings” in this case means works on paper and includes watercolor and oil sketches.
(Images above: Charles-Joseph Natoire [with detail], Il Guercino, Eva Gonzalés, Adrian Zingg, Giovan Battista Dell’Era, Jean-Francois Millet, Adolph Menzel, William Callow [with detail])