Perhaps you should try some spelling variations:
"Foundations of modelos economicos sociales" » "Foundations of modelos economico social", "Foundations of modelos economicos spines", "Foundations of modelos conflictos sociales"
"Foundations of orden economico series" » "Foundations of orden economica serie", "Foundations of orden economico spines", "Foundations of orden economico sociales"

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: "((\"Foundations of modelos economicos sociales\") OR (\"Foundations of orden economico series\"))~".
• Removing quotes may allow a broader search: (( Foundations of modelos economicos sociales ) OR ( Foundations of orden economico series ))~.
• Adding a wildcard symbol may retrieve word variants: (("Foundations of modelos economicos sociales") OR ("Foundations of orden economico series"))*.