Perhaps you should try some spelling variations:
military part » military art, military a, military acts
19th century » 18th century, 20th century
ref history » reef history, brief history, bief history
2.1 19th » 2019 19th, 2018 19th, 2012 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 part AND science %ref history %2.1 19th century%22.
• Adding a wildcard symbol may retrieve word variants: %military part and science %ref history %2.1 19th century%22*.