Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
hang cong » dang cong, hang nong, bang cong
trang va » tran van
cong san » cong tac
phan cau » phan dau, phan cac, phan tu
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu sach - canh ((trang va) or (hang va)) hang cong san ((phan cau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - canh ((trang va) OR (hang va)) hang cong san ((phan cau) OR (toan cau)).
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - canh ((trang va) or (hang va)) hang cong san ((phan cau) or (toan cau))*.