Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
dang xay » dang van, van xay
tham soc » cham soc, tham nuoc, thai son
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
xay hoi » xa hoi, tay hoi, cay phoi
sac ky » cac ky
soc va » hoc va, loc va, doc va
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) OR (sai ky)) dang xay hoi. ((hieu quan) or (hieu qua)) tham soc va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sac ky) OR (sai ky)) dang xay hoi. ((hieu quan) OR (hieu qua)) tham soc va hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sac ky) OR (sai ky)) dang xay hoi. ((hieu quan) or (hieu qua)) tham soc va hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: te ((sac ky) OR (sai ky)) dang xay hoi. ((hieu quan) or (hieu qua)) tham soc va hanh vi luu tre*.