Perhaps you should try some spelling variations:
"public administration" » "publico administration" (Expand Search), "publicas administration" (Expand Search), "publicos administration" (Expand Search), "public administracao" (Expand Search)
"publica administration" » "publicoa administration" (Expand Search), "publicasa administration" (Expand Search), "publicosa administration" (Expand Search), "publica administracao" (Expand Search)
"publicoos administration" » "publicooos administration" (Expand Search), "publicasoos administration" (Expand Search), "publicosoos administration" (Expand Search), "publicoos administracao" (Expand Search), "publicos administration" (Expand Search), "publico administration" (Expand Search), "publicas administration" (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 (\"publicoos administration\"))))~".
• Removing quotes may allow a broader search: (( public administration ) OR ((( publica administration ) OR ( publicoos administration ))))~.
• Adding a wildcard symbol may retrieve word variants: (("public administration") OR ((("publica administration") OR ("publicoos administration"))))*.