Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
dung cong » dung trong
mang vat » bang vat, cang vat, hang vat
dang vat » dang van, dong vat, dang nhat
cong van » cong vang, cong san, song van
van tan » van tuan, van ban, van tai
tan cau » toan cau, van cau, tan ca

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quan) OR (hieu qua)) - nhanh ((mang vat) OR (dang vat)) dung cong van tan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quan) or (hieu qua)) - nhanh ((mang vat) OR (dang vat)) dung cong van tan cau~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quan) or (hieu qua)) - nhanh ((mang vat) OR (dang vat)) dung cong van tan cau*.