Postmodern architecture is a style or movement which emerged in the late 1950s as a reaction against the austerity, formality, and lack of variety of modern architecture, particularly in the international style advocated by Philip Johnson and Henry-Russell Hitchcock. The movement was introduced by the architect and urban planner Denise Scott Brown and architectural theorist Robert Venturi in their 1972 book Learning from Las Vegas. The style flourished from the 1980s through the 1990s, particularly in the work of Scott Brown & Venturi, Philip Johnson, Charles Moore and Michael Graves. In the late 1990s, it divided into a multitude of new tendencies, including high-tech architecture, neo-futurism, new classical architecture, and deconstructivism.^[1] However, some buildings built after this period are still considered postmodern.^[2]