Perhaps you should try some spelling variations:
"theology, doctrinal / history / 18th century" » "theology, doctrines / history / 18th century"
"geology, doctrinal / history / 18th century" » "geology, doctrines / history / 18th century"

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: (("theology, doctrinal / history / 18th century") OR ((("geology, doctrinal / history / 18th century") OR ("geology, doctrine / history / 18th century")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"theology, doctrinal / history / 18th century\") or (((\"geology, doctrinal / history / 18th century\") OR (\"geology, doctrine / history / 18th century\"))))".
• Removing quotes may allow a broader search: (( theology, doctrinal / history / 18th century ) or ((( geology, doctrinal / history / 18th century ) OR ( geology, doctrine / history / 18th century )))).
• Adding a wildcard symbol may retrieve word variants: (("theology, doctrinal / history / 18th century") or ((("geology, doctrinal / history / 18th century") OR ("geology, doctrine / history / 18th century"))))*.