Perhaps you should try some spelling variations:
wang yang » wang yan, wang liang, wang yanling
oil front » oil from, die front
line flow » linear flow, plane flow, line how
zhong tai » hong tan, hong hai, zhong zhi
yang can » yang fan, yang dean, yang yang
line pll » line call, line plot, line plus
wong yue » wang yue, hong yu
can oil » can soils, can only, corn oil

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

• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang can oil front ((line pll) OR (line flow)) ((zhong tai) OR (wong yue)) ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang can oil front ((line pll) or (line flow)) ((zhong tai) or (wong yue)) ;*.