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)
"publicoosa administration" » "publicooosa administration" (Expand Search), "publicasoosa administration" (Expand Search), "publicosoosa administration" (Expand Search), "publicoosa administracao" (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 ("publicoosa administration"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"public administration\") OR (\"publica administration\"))) OR (\"publicoosa administration\"))".
• Removing quotes may allow a broader search: (((( public administration ) OR ( publica administration ))) OR ( publicoosa administration )).
• Adding a wildcard symbol may retrieve word variants: (((("public administration") OR ("publica administration"))) OR ("publicoosa administration"))*.