JOHNSON, R. (1995). Ralph Johnson of perkins and will building and projects. Rizzoli.
Lua i Stíl Chicago (17ú heag.)JOHNSON, Ralph. Ralph Johnson of Perkins and Will Building and Projects. New York: Rizzoli, 1995.
Lua MLA (9ú heag.)JOHNSON, Ralph. Ralph Johnson of Perkins and Will Building and Projects. Rizzoli, 1995.
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