CNN  —  Visitors to European galleries with an interest in pioneering women artists will have plenty of choice this summer, with a series of new exhibitions featuring some of the biggest names in 20th century art. Fantastical sculptures and dreamlike drawings by the late French artist Louise Bourgeois, famed for her towering spiders, are on display at the Courtauld Gallery in London. Elsewhere in Spain, the Guggenheim Museum Bilbao is hosting a solo exhibition of American collagist and