Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tham soc » cham soc, tham nuoc, thai son
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
luu tre » luu tru, cuu tre, luy tre
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te sach » toc sach
soc va » hoc va, loc va, doc va
vi luu » vi lua
te sac » te cac, te san

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