Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
van luong » van duong, nang luong, van chuong
van cuong » van chuong, van duong, van cong
cong lap » cong luan, cong lang, cong tac
dan can » dan chan, dan canh, dan ca
can cau » van cau, ban cau, ca cau

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 - thanh cong lap ((van luong) OR (van cuong)) dan can cau~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - thanh cong lap ((van luong) or (van cuong)) dan can cau*.