Perhaps you should try some spelling variations:
military actions » military relations, military aviation, military pensions
imf history » brief history
2f history » etf history, ref history, tnf history
2018 19th » 2018 15th, 2018 14th, 2018 9th
2.1 19th » 2019 19th, 2012 19th, 2016 19th

Try widening your search to All Fields.

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: %military actions AND science %((2f history) OR (imf history)) %((2.1 19th) OR (2018 19th)) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%military actions and science %((2f history) OR (imf history)) %((2.1 19th) or (2018 19th)) century%22".
• Adding a wildcard symbol may retrieve word variants: %military actions and science %((2f history) OR (imf history)) %((2.1 19th) or (2018 19th)) century%22*.