Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
dung thang » hung thang, cung thang, dung thuong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
manh hung » anh huong
hung phan » huong phan, nhung phan, dung phan
phan cong » thanh cong
dung dat » dung va, dung tai
pha tap » pham tai

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 - manh hung phan cong ((dung thang) or (dung dat)) pha tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - manh hung phan cong ((dung thang) OR (dung dat)) pha tap.
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - manh hung phan cong ((dung thang) or (dung dat)) pha tap*.