Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
nhung cong » dung cong, thong cong, hang cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tranh cua » doanh cua, manh cua
cua nhung » va nhung
manh toan » thanh toan, anh tuan, tinh toan
van than » van thanh, van thang, van tuan

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 - canh tranh cua nhung cong ((manh toan) or (van than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - canh tranh cua nhung cong ((manh toan) OR (van than)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - canh tranh cua nhung cong ((manh toan) or (van than)) cao*.