Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang cac » nang cao, bang cac, hang cac
cac khoi » cac thoi, cac khoan, cach thoi
te sach » toc sach
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
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: ((te sach) OR (thu sach)) ky nang cac khoi. hieu va ((pham duy) OR (pham duc)) va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (thu sach)) ky nang cac khoi. hieu va ((pham duy) OR (pham duc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (thu sach)) ky nang cac khoi. hieu va ((pham duy) OR (pham duc)) va hanh vi cua tre*.