Perhaps you should try some spelling variations:
strain relationship » student relationship (Expand Search)
strain relations » strait relations (Expand Search), strain relaxation (Expand Search), traits relations (Expand Search)
state relations » states relations (Expand Search), state regulation (Expand Search), strait relations (Expand Search)
hole state » hole ststem (Expand Search), how state (Expand Search), idle state (Expand Search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"china–hole state relations) OR (\\"china–holy ((strain relations) OR (strain relationship))))\"".
• Removing quotes may allow a broader search: (( china–hole state relations) OR ( china–holy ((strain relations) OR (strain relationship)))).