Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van cau » van dau, van hau, van chat
duc van » duc va, duc manh, duc phan
cuc tu » cuc du, luc tu, duc tu

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: su sach ty ((nang xa) OR (lang xa)) hoi. hieu van cau ((duc van) OR (duc tan)) thanh tai cuc tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) or (lang xa)) hoi. hieu van cau ((duc van) OR (duc tan)) thanh tai cuc tu~".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (lang xa)) hoi. hieu van cau ((duc van) OR (duc tan)) thanh tai cuc tu*.