Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
te sach » toc sach
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc 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: ((te sach) or (thu sach)) ky nang ma hoi. hieu va cam ((xuc va) OR (luc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thu sach)) ky nang ma hoi. hieu va cam ((xuc va) OR (luc 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 ma hoi. hieu va cam ((xuc va) OR (luc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thu sach)) ky nang ma hoi. hieu va cam ((xuc va) OR (luc va)) hanh vi cua tre*.