Perhaps you should try some spelling variations:
thanh trung » thanh tung
cong thanh » dong thanh, cong trinh, cong tan
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trung cua » truong cua, trung tuan, trung cap
so thiet » soc thiet, hoa thiet, tao thiet
cong san » cong tac
toan ban » van ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((so thiet) OR (hoc thiet)) tach - thanh trung cua ban ((cong thanh) or (cong san)) toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so thiet) OR (hoc thiet)) tach - thanh trung cua ban ((cong thanh) OR (cong san)) toan ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so thiet) OR (hoc thiet)) tach - thanh trung cua ban ((cong thanh) or (cong san)) toan ban*".