Perhaps you should try some spelling variations:
nhanh mang » nhanh lang, hanh mang, nhanh quang
hieu quan » lieu quan, thien quan, lien quan
mang vat » dang vat, bang vat, cang vat
vat dung » van dung, va dung, viet dung
cong van » cong vang, cong san, cong tan
song van » hoang van, trong van, duong van
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 dung ((cong van) OR (song 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 dung ((cong van) OR (song van)) tan cau~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quan) or (hieu qua)) - nhanh mang vat dung ((cong van) OR (song van)) tan cau*.