Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
hanh dung » thanh dung, anh dung, hanh dong
cong vang » cong lang, cong quang, cong ngang
dung van » duong van, dung va, dang van
van nang » van quang, van ban, van dong
cong van » cong san, song van, cong tan
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 dung van nang ((cong van) OR (cong vang)) than cau~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh dung van nang ((cong van) or (cong vang)) than cau*.