A sketch signed by Paul Delvaux is for sale on Ebay.com.
The first image is of that sketch which is signed "a Rene Micha pour la naissance de Venus P. DELVAUX 49."
The second image is of a painting by Paul Delvaux also titled La Naissance de Venus.
The third image is a painting titled The Greeting which shows a similar woman and a man in a bowler hat.
The woman in the left foreground of The Great Sirens is rendered in a similar way to the woman in the sketch. A larger image is at the Met Museum webpage.
A larger image is available at tendreams.org along with many others, also at Askart.com. Other images are art a page dedicated to walking as portrayed in art. A more developed sketch can be seen at the National Galleries of Scotland page.
Paul Delvaux: Surrealizing the Nude (Reaktion Books - Essays in Art and Culture)
PAUL DELVAUX - CAHIER NO. 2: DESSINS ET GRAVURES 1966-1969 - WITH AN ORIGINAL LITHOGRAPHIC COVER
Drawings of Paul Delvaux
Paul Delvaux: Oil paintings, watercolors, drawings, lithographs, etchings
Le pays mosan de Paul Delvaux (French Edition)
PAUL DELVAUX Graphic Work.
PAUL DELVAUX: L'Homme, Le Pientre, Psychologie d'un Art (Text in French)
Paul Delvaux: Der Mensch, Der Maler.
The last image is another work on paper Les Mysterieuses. It sold at Christies for $174,000.