Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
van nhung » van nhuong, va nhung, van hung
cong van » cong vang, song van, cong tan
cong san » cong tac
san toan » van toan, dan toan, manh toan
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 (thien hach)) - thanh cong van nhung cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - thanh cong van nhung cong san toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (thien hach)) - thanh cong van nhung cong san toan cau*.