Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
thanh tung » thanh cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
dung cong » dung trong
tung cua » trung cua, tuong cua, dung cua
dan phan » doan phan, dan chan, dam phan
van phan » van phong, van thanh, luan phan

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