Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh tranh » canh tranh, hanh trinh, hanh trang
duong manh » duong van
dong thanh » truong thanh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tranh cua » doanh cua, manh cua
cua nhung » va nhung
cong manh » cong danh, cong thanh, hoang manh
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 thiet tach - hanh tranh cua nhung ((((cong manh) OR (duong manh))) or (dong thanh)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - hanh tranh cua nhung ((((cong manh) OR (duong manh))) OR (dong thanh)) toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh tranh cua nhung ((((cong manh) OR (duong manh))) or (dong thanh)) toan cau*".