Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
thieu sach » chieu sach, thien hach, hieu cach
dan nhung » ban nhung, san nhung, doanh nhung
dap nhung » vap nhung, va nhung, dap ung
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 thanh)) - anh huong ((dan nhung) OR (dap nhung)) cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien thanh)) - anh huong ((dan nhung) OR (dap nhung)) cong san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (thien thanh)) - anh huong ((dan nhung) OR (dap nhung)) cong san toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (thien thanh)) - anh huong ((dan nhung) OR (dap nhung)) cong san toan cau*.