A handful of U.S. museums sent collection artworks to the auction block at a Sotheby's American art sale that totalled $15 million on Wednesday. Women artists in the sale including Mary Cassatt, Georgia O'Keeffe, Grandma Moses and Gertude Abercrombie brought big prices for some small-sized works overall. Although some of the sales could be earmarked to fund new acquisitions, the sell-off from public institutions falls within a two-year period in which museum association guidelines .