Perhaps you should try some spelling variations:
tieu sach » chieu sach, dien sach, te sach
hanh mang » nhanh mang, hanh trang, nhanh lang
bang cong » dang cong, bang song, dung cong
hang cong » dang cong, hang nong, thanh cong
mang cua » manh cua, dung cua, ban cua
van toan » van tuan, van tan, van thanh
dan than » dan chan, ban than, van than

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu sach - hanh mang cua ((bang cong) OR (hang cong)) ((van toan) OR (dan than)) cao~".
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - hanh mang cua ((bang cong) OR (hang cong)) ((van toan) OR (dan than)) cao*.