Perhaps you should try some spelling variations:
sang quang » hang quang, tang quang, van quang
dang quang » dung quang, nang quan, dang hung
hieu luat » hieu qua
quan tren » quan trong, quang tran, quan tri
tren hoat » trien hoat, trong hoat, thien hoat
dung nam » dong nam, dung lam, sung nam
van hieu » cao hieu
nam van » nam dan, nam va, pham van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin dung nam van hieu luat ) or ( tinh ((sang quang) or (dang quang)) quan tren hoat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung nam van hieu luat ) OR ( tinh ((sang quang) OR (dang quang)) quan tren hoat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung nam van hieu luat ) or ( tinh ((sang quang) or (dang quang)) quan tren hoat ))*.