Perhaps you should try some spelling variations:
tham nuoc » thay nuoc, thoat nuoc, nha nuoc
hieu quan » lieu quan, thien quan, lien quan
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
va hanh » va thanh, va danh, ban hanh
luu tre » luu tru, cuu tre, luy tre
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang xa hoi. ((hieu quan) or (hieu qua)) tham nuoc ((va hanh) OR (van hanh)) vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang xa hoi. ((hieu quan) OR (hieu qua)) tham nuoc ((va hanh) OR (van hanh)) vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky nang xa hoi. ((hieu quan) or (hieu qua)) tham nuoc ((va hanh) OR (van hanh)) vi luu tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky nang xa hoi. ((hieu quan) or (hieu qua)) tham nuoc ((va hanh) OR (van hanh)) vi luu tre*.