Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
nhung cong » dung cong, thong cong, hang cong
thanh chau » thanh cha, thanh cham, thanh chu
hieu cach » hieu cac, chieu sach, hieu ca
tranh va » tranh van, trang va, trinh va
cong tan » cong tac, cong san, cong thanh
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) OR (hieu cach)) - canh tranh va nhung cong tan ((thanh chau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - canh tranh va nhung cong tan ((thanh chau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (hieu cach)) - canh tranh va nhung cong tan ((thanh chau) or (toan cau))".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (hieu cach)) - canh tranh va nhung cong tan ((thanh chau) or (toan cau))*.