Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
thanh tung » thanh cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tung cao » nung cao, truong cao, trung cap
cong dan » cong san, cong tan, cong dong
than cau » phan cau, than cap, thanh chau
toan cau » toan cao, toan ban, toan tap
cao han » cao nhan, cao phan, cao van

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 tung cao han ((cong dan) or (huong dan)) ((than cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - thanh tung cao han ((cong dan) OR (huong dan)) ((than cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - thanh tung cao han ((cong dan) or (huong dan)) ((than cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - thanh tung cao han ((cong dan) or (huong dan)) ((than cau) OR (toan cau))*.