Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
hang cong » dang cong, hang nong, bang cong
dung cong » dung trong
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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 - thanh ((trung cua) or (trung cap)) ((hang cong) or (dung cong)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - thanh ((trung cua) OR (trung cap)) ((hang cong) OR (dung cong)) dan than cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - thanh ((trung cua) or (trung cap)) ((hang cong) or (dung cong)) dan than cau*.