Perhaps you should try some spelling variations:
wang dan » wang yan, wang ban, wang yidan
dan than » dan phan, van thanh
oil coal » oil oil, oil can, oil chad
qiang li » liang li, qiang niu, ling li
hong hai » shang hai, zhong tai, dang hai
wang yue » wong yue, wang hua, wang yan
cost » costs

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang dan than ((oil coal) OR (oil cost)) qiang li ((hong hai) or (wang yue)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang dan than ((oil coal) OR (oil cost)) qiang li ((hong hai) OR (wang yue)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang dan than ((oil coal) OR (oil cost)) qiang li ((hong hai) or (wang yue)) ;".
• Adding a wildcard symbol may retrieve word variants: wang dan than ((oil coal) OR (oil cost)) qiang li ((hong hai) or (wang yue)) ;*.