Perhaps you should try some spelling variations:
"last layer theory" » "last order theory", "last prayer theory", "rust layer theory", "elastic layer theory"
"just war theory" » "just laser theory", "post war theory", "just a theory"
"last war theory" » "last laser theory", "post war theory"

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: (("just war theory") OR ((("last war theory") OR ("last layer theory")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"just war theory\") or (((\"last war theory\") OR (\"last layer theory\"))))".
• Removing quotes may allow a broader search: (( just war theory ) or ((( last war theory ) OR ( last layer theory )))).
• Adding a wildcard symbol may retrieve word variants: (("just war theory") or ((("last war theory") OR ("last layer theory"))))*.