Sustainable landscape design in arid climates : proceedings of a symposium jointly organized by the Aga Khan Trust for Agriculture, the Center for Advanced Study in the Visual Arts/National Gallery of art, Studies in Landscape Architecture, Dumbarton Oaks, the Lemelson Center for Innovation at the Smithsonian Institution's National Museum for American History, Graduate School of Design, Harvard University, and the National Building Museum held at Dumbarton Oaks on 7 December 1996.