Perhaps you should try some spelling variations:
dong yang » dong hoang, wang yang, yang yang
yang yana » yang yang, wang yan, yang anda
yana hua » wang hua, tan hua, ya hua
phan thi » pham thi, tran thi
nhan thi » ha thi, nga thi, pham thi
dang thi » dang hai
hong yu » wong yue

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

• Performing a fuzzy search may retrieve terms with similar spellings: dong yang yana hua (rest or test) ((((phan thi) or (nhan thi))) or (dang thi)) hong yu ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: dong yang yana hua (rest OR test) ((((phan thi) OR (nhan thi))) OR (dang thi)) hong yu ;.
• Adding a wildcard symbol may retrieve word variants: dong yang yana hua (rest or test) ((((phan thi) or (nhan thi))) or (dang thi)) hong yu ;*.