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

• If you are trying to use Boolean operators, they must be ALL CAPS: %new spain %((2f politics) OR (21 politics)) AND government %2f 18th century %((2 sources) OR (21 sources))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%new spain %((2f politics) OR (21 politics)) and government %2f 18th century %((2 sources) or (21 sources))%22".
• Adding a wildcard symbol may retrieve word variants: %new spain %((2f politics) OR (21 politics)) and government %2f 18th century %((2 sources) or (21 sources))%22*.