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)
"publicoaa administration" » "publicooaa administration" (Expand Search), "publicasoaa administration" (Expand Search), "publicosoaa administration" (Expand Search), "publicoaa administracao" (Expand Search), "publico administration" (Expand Search), "publicas administration" (Expand Search), "publicos administration" (Expand Search)

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

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