Perhaps you should try some spelling variations:
wang dan » wang yan, wang yidan, wang yang
wang ban » wang yan, wang yang, bang bang
than oil » than coal, than only, than one
oil coal » oil cost, oil oil, oil can
liang li » ling li, qiang li, liang wei
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 ban)) than oil coal liang li ((hong hai) or (wang yue)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang dan) OR (wang ban)) than oil coal liang li ((hong hai) OR (wang yue)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang dan) OR (wang ban)) than oil coal liang li ((hong hai) or (wang yue)) ;".
• Adding a wildcard symbol may retrieve word variants: ((wang dan) OR (wang ban)) than oil coal liang li ((hong hai) or (wang yue)) ;*.