Perhaps you should try some spelling variations:
credits creating » credit creating, credit rating, creation creating
change scoping » change becoming, change mapping, change helping
change coping » change mowing, change comparing, change becoming
dong nan » dong yang, dong sin, dong bin
yan 2 » yan _
yan 4 » yang 4, yan _, ban 4

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: dong nan ((yan 2) OR (yan 4)) credits creating ((change coping) OR (change scoping)) shu ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "dong nan ((yan 2) OR (yan 4)) credits creating ((change coping) or (change scoping)) shu ;~".
• Adding a wildcard symbol may retrieve word variants: dong nan ((yan 2) OR (yan 4)) credits creating ((change coping) or (change scoping)) shu ;*.