Wekerle, G. R. (1998). Safe Cities Guidelines For Planning, Design And Management Gerda R. Wekerle, Carolyn Whitzman. Van Nostrand Reinhold.
Lua i Stíl Chicago (17ú heag.)Wekerle, Gerda R. Safe Cities Guidelines For Planning, Design And Management Gerda R. Wekerle, Carolyn Whitzman. Van Nostrand Reinhold, 1998.
Lua MLA (8ú heag.)Wekerle, Gerda R. Safe Cities Guidelines For Planning, Design And Management Gerda R. Wekerle, Carolyn Whitzman. Van Nostrand Reinhold, 1998.
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