Perhaps you should try some spelling variations:
"public administration" » "publica administration" (Expand Search), "publico administration" (Expand Search), "publicas administration" (Expand Search), "public administracao" (Expand Search)
"publicaas administration" » "publicaaas administration" (Expand Search), "publicoaas administration" (Expand Search), "publicasaas administration" (Expand Search), "publicaas administracao" (Expand Search), "publicas administration" (Expand Search), "publica administration" (Expand Search), "publicos administration" (Expand Search)
"publicoa administration" » "publicaoa administration" (Expand Search), "publicooa administration" (Expand Search), "publicasoa administration" (Expand Search), "publicoa administracao" (Expand Search), "publica administration" (Expand Search), "publico administration" (Expand Search), "publicos 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 (((\"publicaas administration\") OR (\"publicoa administration\"))))~".
• Removing quotes may allow a broader search: (( public administration ) OR ((( publicaas administration ) OR ( publicoa administration ))))~.
• Adding a wildcard symbol may retrieve word variants: (("public administration") OR ((("publicaas administration") OR ("publicoa administration"))))*.