Perhaps you should try some spelling variations:
thanh trung » thanh tung
hoc thiet » hoc thieu, hoc thuyet, hoc hien
so thiet » soc thiet, hoa thiet, tao thiet
trung ha » trung hoc, trung tam, trung cap
ha nhung » hoa nhung, hay nhung, pha nhung
cong san » cong tac
toan cao » toan ban, toan 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) or (so thiet)) tach - thanh trung ha nhung ((cong san) or (huong dan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thiet) OR (so thiet)) tach - thanh trung ha nhung ((cong san) OR (huong dan)) toan cao.
• Adding a wildcard symbol may retrieve word variants: ((hoc thiet) or (so thiet)) tach - thanh trung ha nhung ((cong san) or (huong dan)) toan cao*.