Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
hanh tranh » canh tranh, hanh trinh, hanh trang
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trong tan » trong quan, trong cac, trong ca
cua dung » cua dang, cua dong, qua dung
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 hach - hanh tranh ((cua dung) or (cua cong)) ((trong tan) or (thong quan)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - hanh tranh ((cua dung) OR (cua cong)) ((trong tan) OR (thong quan)) toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - hanh tranh ((cua dung) or (cua cong)) ((trong tan) or (thong quan)) toan cau*.