Perhaps you should try some spelling variations:
doanh doanh » toan doanh, doanh hoan, doanh thanh
thiet hach » thien hach, thuyet hach, thiet hai
thanh chau » thanh cha, thanh cham, thanh chu
hoc thiet » hoc thieu, hoc thuyet, hoc hien
doanh va » doan va, doanh tai, doanh cua
cong ban » cong bang, cong tan, cong dan
cong san » cong tac

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 - doanh doanh va nhung ((cong ban) or (cong san)) thanh chau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - doanh doanh va nhung ((cong ban) OR (cong san)) thanh chau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - doanh doanh va nhung ((cong ban) or (cong san)) thanh chau*.