Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, bieu hien
danh dai » danh dau, danh di, danh sai
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
lao va » tao va, cao va, bao va
lo va » lo van, ly va, le 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 lang xa hoi. ((hieu thien) OR (dieu khien)) cac ((lo va) or (lao va)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. ((hieu thien) OR (dieu khien)) cac ((lo va) OR (lao va)) danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. ((hieu thien) OR (dieu khien)) cac ((lo va) or (lao va)) danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. ((hieu thien) OR (dieu khien)) cac ((lo va) or (lao va)) danh dai cua tre*.