Perhaps you should try some spelling variations:
natural phonology » natural theology, natural immunology, general phonology
1720 early » 1727 early, 1820 early, 1770 early
12 early » 2 early, 11 early, 1722 early
20 early » 1820 early
10 early » 1800 early, 1820 early, 1770 early

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: %natural phonology %((12 early) OR (((((20 early) OR (1720 early))) OR (10 early)))) works to 1800%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%natural phonology %((12 early) or (((((20 early) OR (1720 early))) or (10 early)))) works to 1800%22".
• Adding a wildcard symbol may retrieve word variants: %natural phonology %((12 early) or (((((20 early) OR (1720 early))) or (10 early)))) works to 1800%22*.