Best-selling author Michael Crichton approached art in the same way he did his writing - through extensive research - but also by developing close friendships with many of the artists whose works he collected. The popular thriller writer died in 2008, leaving behind such blockbusters as “Jurassic Park,” “The Andromeda Strain” and the TV series “ER.” But he also left a 20th century art collection that features some of pop art's best known artists, including Jasper Johns, Roy Lichtenstein and Claes Oldenburg. Crichton's family is selling about 80 percent of the collection at Christie's auction house in New York on May 11-12. Among the highlights is Jasper Johns' “Flag,” a rendition of the American flag that Crichton bought from the artist in 1974, and which decorated the writer's Beverly Hills bedroom. It was last exhibited in 1992-93 at the Royal Academy of Arts in London. The “Flag” has a pre-sale estimate of $10 million to $15 million, but Christie's believes it will set a new world record for the artist. About 70 of the 100 works from the collection, including paintings by Jeff Koons, Pablo Picasso and Robert Rauschenberg, will be displayed at Christie's Rockefeller Center galleries from Friday through April 13. Oldenburg's 1970 “Three Way Plug Soft Sculpture,” which he purchased from the artist, is estimated at $250,000 to $350,000. Lichtenstein's “Girl in Water” has a pre-sale estimate of $800,000 to $1.2 million, while Rauschenberg's “Studio Painting” is estimated at $6 million to $9 million.