Perhaps you should try some spelling variations:
20 politics » 2 politics, 10 politics, 20 political
22 sources » 2.2 sources, 252 sources, 12 sources
21 sources » 2.1 sources, 11 sources, 21 source
1 sources » 3 sources

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: %((22new spain) OR (new spain)) %20 politics AND government %2f 18th century %((((22 sources) OR (1 sources))) OR (((21 sources) OR (2 sources))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((22new spain) OR (new spain)) %20 politics and government %2f 18th century %((((22 sources) or (1 sources))) or (((21 sources) or (2 sources))))%22".
• Adding a wildcard symbol may retrieve word variants: %((22new spain) OR (new spain)) %20 politics and government %2f 18th century %((((22 sources) or (1 sources))) or (((21 sources) or (2 sources))))%22*.