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)
"publicaaa administration" » "publicaaaa administration" (Expand Search), "publicoaaa administration" (Expand Search), "publicasaaa administration" (Expand Search), "publicaaa administracao" (Expand Search), "publica administration" (Expand Search), "publicas administration" (Expand Search)
"publicaaaas administration" » "publicaaaaas administration" (Expand Search), "publicoaaaas administration" (Expand Search), "publicasaaaas administration" (Expand Search), "publicaaaas administracao" (Expand Search), "publicaas administration" (Expand Search), "publicasas 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 (((\"publicaaa administration\") OR (\"publicaaaas administration\"))))~".
• Removing quotes may allow a broader search: (( public administration ) OR ((( publicaaa administration ) OR ( publicaaaas administration ))))~.
• Adding a wildcard symbol may retrieve word variants: (("public administration") OR ((("publicaaa administration") OR ("publicaaaas administration"))))*.