Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
nang cac » nang cao, bang cac, hang cac
cac khoi » cac thoi, cac khoan, cach thoi
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
va cham » va chat, va tham
cua tre » cua te, cuu tre, cua triet
xuc va » tuc va, luc va, xac va
vi cua » vai cua, di cua

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

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