Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
doanh phan » doanh nhan, doan phan, doanh thanh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
dao thang » dao thanh, bao thang, dai thang
cong dao » cuong dao, cong dan, dong dao
dan phan » doan phan, dan chan, van 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 tach - thanh cong dao thang long ((dan phan) or (doanh phan)) lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - thanh cong dao thang long ((dan phan) OR (doanh phan)) lap*.