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