Perhaps you should try some spelling variations:
"Función de costes Cobb-Douglas" » "Función de costas Cobb-Douglas" (Expand Search), "Función de cortes Cobb-Douglas" (Expand Search), "Función de cosas Cobb-Douglas" (Expand Search)
"Función de costos Cobb-Douglas" » "Función de costas Cobb-Douglas" (Expand Search), "Función de cosas Cobb-Douglas" (Expand Search), "Función de costa Cobb-Douglas" (Expand Search)
cobb » cobo (Expand Search), coba (Expand Search), cbb (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("Función de costes Cobb-Douglas") OR ("Función de costos Cobb-Douglas"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"Función de costes Cobb-Douglas\") OR (\"Función de costos Cobb-Douglas\"))".
• Removing quotes may allow a broader search: (( Función de costes Cobb-Douglas ) OR ( Función de costos Cobb-Douglas )).
• Adding a wildcard symbol may retrieve word variants: (("Función de costes Cobb-Douglas") OR ("Función de costos Cobb-Douglas"))*.