Perhaps you should try some spelling variations:
nphan dang » nhan dang, nhan dan, phan dong
hieu lang » chieu sang, hieu quang, nhieu tang
phan dang » phan dau, phan cong, nhan dan
doc hieu » toc thieu, hoc thieu, hoc hien
dan dung » van dung, tin dung, ap dung
dung dat » dung va, dung tai
phi dau » phan dau
va phi » va chi, va phe, va pha

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 (nphan dang)) dan dung dat va phi dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu lang - ((phan dang) OR (nphan dang)) dan dung dat va phi dau".
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - ((phan dang) OR (nphan dang)) dan dung dat va phi dau*.