Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
hieu va » lieu va, hieu qua
cam tuc » cam xuc, nam thuc, dam thuc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
cam tu » cam thu, nam tu, dam tu
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang x hoi. ((hieu ve) OR (hieu va)) ((cam tuc) or (cam tu)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. ((hieu ve) OR (hieu va)) ((cam tuc) OR (cam tu)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. ((hieu ve) OR (hieu va)) ((cam tuc) or (cam tu)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. ((hieu ve) OR (hieu va)) ((cam tuc) or (cam tu)) va hanh vi cua tre*.