Perhaps you should try some spelling variations:
coal lang » coal plant
wang can » wang yan, wang dan, wang yang
wang ban » wang yan, wang dan, wang yang
oil coal » oil cost, oil oil, oil can
hong hai » shang hai, zhong tai, dang hai
wong yue » wang yue, hong yu
lang li » liang li, ling li, tang li

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

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