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 dung » manh hung, manh tung, anh dung
dung phan » dung nhan, dung luan, dung ha
phan cong » thanh cong
dung dat » dung va, dung tai
phan tap » phan lap, han tap, pha tap

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 dung phan cong ((dung thang) OR (dung dat)) phan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet hach - manh dung phan cong ((dung thang) OR (dung dat)) phan tap".
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - manh dung phan cong ((dung thang) OR (dung dat)) phan tap*.