Perhaps you should try some spelling variations:
xgreat britain » great britain, zgreat britain, great brittain
2f foreign » 2 foreign, 23 foreign, 24 foreign
2f denmark » 2 denmark, 22 denmark, 2.3 denmark
23 denmark » 2.3 denmark, 3 denmark, 13 denmark
1720 early » 1727 early, 1820 early, 1770 early
20 early » 10 early, 1820 early

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: %xgreat britain %2f foreign relations %((2f denmark) OR (23 denmark)) %((20 early) OR (1720 early)) works to 1800%22*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%xgreat britain %2f foreign relations %((2f denmark) or (23 denmark)) %((20 early) OR (1720 early)) works to 1800%22*".