Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
phan dang » phan dau, phan cong, nhan dan
doc hieu » toc thieu, hoc thieu, hoc hien
gian dan » gian lang
dung dat » dung va, dung tai
dat van » dao van, dat va, dam van
van phi » van chi, van phu, van nhi
phi dau » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu lang - ((phan dang) or (gian dan)) tin dung dat van phi dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - ((phan dang) OR (gian dan)) tin dung dat van phi dau.
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - ((phan dang) or (gian dan)) tin dung dat van phi dau*.