Perhaps you should try some spelling variations:
"public administration" » "publica administration" (Expand Search), "publicas administration" (Expand Search), "publicos administration" (Expand Search), "public administracao" (Expand Search)
"publico administration" » "publicao administration" (Expand Search), "publicaso administration" (Expand Search), "publicoso administration" (Expand Search), "publico administracao" (Expand Search), "publica administration" (Expand Search)
"publicoaaa administration" » "publicaoaaa administration" (Expand Search), "publicasoaaa administration" (Expand Search), "publicosoaaa administration" (Expand Search), "publicoaaa administracao" (Expand Search), "publicaaaa 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 (\"publico administration\"))) OR (\"publicoaaa administration\"))~".
• Removing quotes may allow a broader search: (((( public administration ) OR ( publico administration ))) OR ( publicoaaa administration ))~.
• Adding a wildcard symbol may retrieve word variants: (((("public administration") OR ("publico administration"))) OR ("publicoaaa administration"))*.