Perhaps you should try some spelling variations:
wang yang » wang yan, wang liang, wang yanling
yang ban » yang fan, wang ban, yang dean
oil coal » oil cost, oil oil, oil can
plant li » plant life, plant lice, plant oil
hong hai » shang hai, zhong tai, dang hai
wong yue » wang yue, hong yu
ban oil » can oil, oman oil, than oil

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yang ban oil coal plant li ((hong hai) or (wong yue)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang ban oil coal plant li ((hong hai) OR (wong yue)) ;.
• Adding a wildcard symbol may retrieve word variants: wang yang ban oil coal plant li ((hong hai) or (wong yue)) ;*.