Perhaps you should try some spelling variations:
military acts » military art, military actions, military aspects
2f history » imf history, etf history, ref history
2018 19th » 2018 15th, 2018 9th, 2019 19th
2018 14th » 2018 15th, 2018 5th
2.1 19th » 2019 19th, 2012 19th, 2016 19th
2018 4th » 2018 15th

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 acts AND science %2f history %((((2.1 19th) OR (2018 19th))) OR (((2018 14th) OR (2018 4th)))) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%military acts and science %2f history %((((2.1 19th) OR (2018 19th))) or (((2018 14th) or (2018 4th)))) century%22".
• Adding a wildcard symbol may retrieve word variants: %military acts and science %2f history %((((2.1 19th) OR (2018 19th))) or (((2018 14th) or (2018 4th)))) century%22*.