Perhaps you should try some spelling variations:
dinh thai » sinh thai, tinh thai, hinh thai
dinh thi » dinh tri
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
cao hai » cao khai, cao tai, co hai
cua tre » cua te, cuu tre, cua triet

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 cao hai. ((hieu ve) or (hieu van)) cac duc van ((dinh thai) or (dinh thi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hai. ((hieu ve) OR (hieu van)) cac duc van ((dinh thai) OR (dinh thi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hai. ((hieu ve) or (hieu van)) cac duc van ((dinh thai) or (dinh thi)) cua tre*.