LONDON.- Fifty important works by Andy Warhol are on view at the Hay Hill Gallery this summer. The exhibition offers a rare and fascinating insight into Warhols creative mind and working processes, with an unprecedented number of works juxtaposed with their preparatory drawings. Highlights include a unique collection of Andy Warhols Indians (Native Americans) (1986), exhibited alongside the working drawings. These seventeen works of art form an important part of Warhols oeuvre. They provide a rounded study of Warhols graphic process in the 1980s and a fitting manifestation of his later obsession with American culture, particularly the stories, myths and legends of the American West. Based on publicity and archival photographs as well as postcards, Warhol romanticises stereotyped and exploited images of American Indians including Mother and Child, Indian Head Nickel, Plain Indian Shield