Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
toc sach » hoc sach, doc sach, thuoc sach
dau tren » dau tien, dat tren, dau tieng
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
nang xa » nang x, nang ma, mang xa
va dinh » van dinh, va kinh, va tinh
dinh vi » dinh ve, dinh viet, dinh tri
dam tu » nam tu, cam tu, dam thuc
tam tu » nam tu, cam tu, tam thuc
vi dau » vi dai, va dau, bi dau

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: toc sach thue ((nang xa) OR (lang xa)) hoi. hieu va ((dam tu) OR (tam tu)) va dinh vi dau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thue ((nang xa) OR (lang xa)) hoi. hieu va ((dam tu) or (tam tu)) va dinh vi dau tren~".
• Adding a wildcard symbol may retrieve word variants: toc sach thue ((nang xa) OR (lang xa)) hoi. hieu va ((dam tu) or (tam tu)) va dinh vi dau tren*.