Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
hieu cach » hieu cac, chieu sach, hieu ca
dang hung » dang quang, manh hung, dang cong
tranh va » tranh van, trang va, trinh va
hung dan » huong dan, dung dan, tung dan
toan tap » toan ban
va dang » van dang, va nang, va lang

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: hoc ((thieu sach) OR (hieu cach)) - canh tranh va dang hung dan ((van ban) OR (toan tap))~.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cach)) - canh tranh va dang hung dan ((van ban) or (toan tap))*.