Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach
thuat tach » thuat sach, thuat mach, thuat tac
tang thanh » dang thanh, trung thanh, hoang thanh
thanh chau » thanh cha, thanh cham, thanh chu
canh manh » lanh manh, canh tranh, cach mang
dung cong » dung trong
manh cua » doanh cua, ban cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet tach) OR (thuat tach)) - canh manh cua ((dung cong) or (thong thong)) tang thanh chau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (thuat tach)) - canh manh cua ((dung cong) OR (thong thong)) tang thanh chau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) OR (thuat tach)) - canh manh cua ((dung cong) or (thong thong)) tang thanh chau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) OR (thuat tach)) - canh manh cua ((dung cong) or (thong thong)) tang thanh chau*.