Perhaps you should try some spelling variations:
soils coal » soils soil, oil coal
coal lang » coal plant
zhong tai » hong tan, zhong zhi
yan clay » yan clan, cam clay
hong hai » shang hai, dang hai, hong tan
lang li » liang li, ling li, tang li
hong yu » wong yue
wang » wing, wan

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang yan clay soils coal lang li ((((hong hai) or (zhong tai))) or (hong yu)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang yan clay soils coal lang li ((((hong hai) OR (zhong tai))) OR (hong yu)) ;.
• Adding a wildcard symbol may retrieve word variants: wang yan clay soils coal lang li ((((hong hai) or (zhong tai))) or (hong yu)) ;*.