Wikipedia: Modern Architecture - A description of the development and characteristics of the International Modern style of the twentieth century. - http://en.wikipedia.org/wiki/Modern_architecture
Docomomo International - Non-profit organization devoted to the documentation and conservation of buildings, sites and neighbourhoods of the modern movement. Includes aims, activities, publications and conferences. - http://www.docomomo.com/
Villa Cavrois - This plea for the preservation of a landmark of the Modern Movement in France, designed by Robert Mallet-Stevens in 1932, includes a history and photographs. - http://www.nordnet.fr/mallet-stevens/
Italian Futurist Architecture (1909-1944) - The architects, architecture and theory of an avantgarde architectural movement. Italian with English translations beneath. - http://www.rebel.net/~futurist/
Functionalism and the City of Viipuri - A study by E.T. Dankwa of the 1930s Modernist architecture in the then-Finnish city of Viipuri, featuring works like Alvar Aalto's Viipuri Municipal Library. - http://www.greatgridlock.net/Viipuri/viipuri.html
The Canberra House - A history of modernist residential architecture in Australia's capital. House profiles, architect biographies, essays on styles and a history of Canberra. - http://www.canberrahouse.com.au
Modcom - The Modern Committee is a Los Angeles-based volunteer group formed in response to the rapid destruction of post-WWII buildings. Includes listings of endangered and destroyed Modern buildings in southern California. - http://www.modcom.org/