Perhaps you should try some spelling variations:
2 politics » 3 politics, 2 political, 2 politische
2f sources » 2 sources, 20 sources, 22 sources
21 sources » 2.1 sources, 2 sources, 11 sources
f sources » 2 sources, 3 sources, 4 sources
1 sources » 2 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)) %2 politics AND government %2f 18th century %((((2f sources) OR (f sources))) OR (((21 sources) OR (1 sources))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((22new spain) or (new spain)) %2 politics and government %2f 18th century %((((2f sources) OR (f sources))) or (((21 sources) or (1 sources))))%22".
• Adding a wildcard symbol may retrieve word variants: %((22new spain) or (new spain)) %2 politics and government %2f 18th century %((((2f sources) OR (f sources))) or (((21 sources) or (1 sources))))%22*.