Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hien cac » thien cac, vien cac, hieu cac
tu sach » thu sach, su sach, te sach
tinh va » tich va, trinh van, trinh vat
kinh va » kinh van, sinh va, minh va
sach ky » sac ky, sach y, sach ty
cac lao » ca lao, cac loai, cac giao
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa
lao va » tao va, cao va, bao va

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 xa) OR (nang x)) hoi. hieu hien cac lao va ((kinh va) or (tinh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang x)) hoi. hieu hien cac lao va ((kinh va) OR (tinh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang x)) hoi. hieu hien cac lao va ((kinh va) or (tinh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) OR (nang x)) hoi. hieu hien cac lao va ((kinh va) or (tinh va)) cua tre*.