Perhaps you should try some spelling variations:
thanh tang » thanh thang, thanh trang, thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu luch » hieu luat, hieu cach, hieu tuc
hieu luc » hieu luat, hieu qua
ca nhung » cua nhung, cam nhung, va nhung
cong san » cong tac
san phan » san pham, van phan, sat phan
phan dau » phan tu, hang dau
tang ca » tang cua, hang ca, tang ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu luch) or (hieu luc)) - thanh tang ca nhung cong san phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu luch) OR (hieu luc)) - thanh tang ca nhung cong san phan dau.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu luch) or (hieu luc)) - thanh tang ca nhung cong san phan dau*.