Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thu sach » tu sach, thuat sach, thuoc sach
thanh co » thanh do, thanh ca, thanh ho
duc ban » duc van, dua ban, duc man
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
ve cao » va cao, ve bao, ve cac
co cua » con cua, ca cua, cong cua
cua su » qua su

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: thu sach thue ((nang xa) OR (lang xa)) hoi. hieu ve cao ((duc ban) OR (duc tan)) thanh co cua su~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach thue ((nang xa) OR (lang xa)) hoi. hieu ve cao ((duc ban) or (duc tan)) thanh co cua su~".
• Adding a wildcard symbol may retrieve word variants: thu sach thue ((nang xa) OR (lang xa)) hoi. hieu ve cao ((duc ban) or (duc tan)) thanh co cua su*.