Perhaps you should try some spelling variations:
3 politics » 3 political, 3 politische
2f sources » 2 sources, 20 sources, 22 sources
21 sources » 2.1 sources, 2 sources, 11 sources
1 sources » 2 sources, 3 sources

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: "%((22new spain) OR (new spain)) %3 politics AND government %2f 18th century %((2f sources) OR (((21 sources) OR (1 sources))))%22".
• Adding a wildcard symbol may retrieve word variants: %((22new spain) OR (new spain)) %3 politics AND government %2f 18th century %((2f sources) OR (((21 sources) OR (1 sources))))%22*.