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

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