Perhaps you should try some spelling variations:
"public administration" » "publica administration" (Expand Search), "publicas administration" (Expand Search), "public administracao" (Expand Search)
"publico administration" » "publicao administration" (Expand Search), "publicaso administration" (Expand Search), "publico administracao" (Expand Search), "publica administration" (Expand Search)
"publicos administration" » "publicaos administration" (Expand Search), "publicasos administration" (Expand Search), "publicos administracao" (Expand Search), "publicas administration" (Expand Search), "publica administration" (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("public administration") OR ((("publico administration") OR ("publicos administration"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"public administration\") OR (((\"publico administration\") OR (\"publicos administration\"))))*".
• Removing quotes may allow a broader search: (( public administration ) OR ((( publico administration ) OR ( publicos administration ))))*.