Perhaps you should try some spelling variations:
thinh tai » chinh tai, trinh tai, thanh tai
hieu van » hieu va, thien van, lieu va
hinh tai » chinh tai, hinh thai, hinh bai
tu sach » thu sach, su sach, te sach
cac van » cac dan
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
cuc ban » cua ban, cac ban, cuu ban
van cam » van nam, van lam, van cau
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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 ky nang ma hoi. hieu van cam ((cuc ban) or (cac van)) ((hinh tai) or (thinh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu van cam ((cuc ban) OR (cac van)) ((hinh tai) OR (thinh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. hieu van cam ((cuc ban) or (cac van)) ((hinh tai) or (thinh tai)) cua tre*.