Perhaps you should try some spelling variations:
bieu hien » dieu hien, dieu khien, bien phien
hieu hien » dieu hien, chieu chien, dieu khien
dinh vai » dinh van, dinh vi, dinh va
su sach » so sach, vu sach
nang xa » nang x, nang ma, mang xa
vai cua » dai cua, hai cua, lai cua
lang xa » lang ha, dang xay, lang van
va dinh » van dinh, va kinh, va tinh
sach ky » sac ky, sach y, sach ty
cac bo » bac bo, cac co
cua te » cua tu
bo va » bao va, do va, so va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (lang xa)) hoi. ((hieu hien) OR (bieu hien)) cac bo va dinh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang xa)) hoi. ((hieu hien) OR (bieu hien)) cac bo va dinh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (lang xa)) hoi. ((hieu hien) OR (bieu hien)) cac bo va dinh vai cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (lang xa)) hoi. ((hieu hien) OR (bieu hien)) cac bo va dinh vai cua te*.