Perhaps you should try some spelling variations:
"public administration" » "publicas administration" (Expand Search), "publicos administration" (Expand Search), "public administracao" (Expand Search)
"publica administration" » "publicasa administration" (Expand Search), "publicosa administration" (Expand Search), "publica administracao" (Expand Search)
"publico administration" » "publicaso administration" (Expand Search), "publicoso administration" (Expand Search), "publico administracao" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"public administration\") OR (((\"publica administration\") OR (\"publico administration\"))))~".
• Removing quotes may allow a broader search: (( public administration ) OR ((( publica administration ) OR ( publico administration ))))~.
• Adding a wildcard symbol may retrieve word variants: (("public administration") OR ((("publica administration") OR ("publico administration"))))*.