Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
hanh dang » hanh dong, anh dang, hanh dung
cong sang » cong lang, cong vang, cong bang
dang van » hoang van, hang va
van nang » van quang, van ban, van dong
cong san » cong tac
than cau » toan cau, phan cau, than cap

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 - hanh dang van nang ((cong san) OR (cong sang)) than cau~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh dang van nang ((cong san) or (cong sang)) than cau*.