Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
tu sach » thu sach, su sach, te sach
dinh va » dinh van, dinh ve, tinh va
va dinh » van dinh, va kinh, va tinh
sach ky » sac ky, sach y, sach ty
cac lao » cac loai, cac giao, cac lang
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet
ca lao » cua lao, ca dao, ca cao
va cua » va chua, via cua, ca cua

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

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