Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh trinh » canh tranh, hanh chinh
hoc thiet » hoc thieu, hoc thuyet, hoc hien
cua phong » cua phuong, cua khong, chau phong
cuu phong » cuu phuong, cuu chong, luu phong
tran manh » tran minh, tran thanh, tran van
cong dan » cong san, cong tan, huong dan
than man » than ma, thanh san, than phan

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 - hanh trinh ((cua phong) or (cuu phong)) cong dan ((than man) OR (tran manh))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - hanh trinh ((cua phong) OR (cuu phong)) cong dan ((than man) OR (tran manh)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh trinh ((cua phong) or (cuu phong)) cong dan ((than man) OR (tran manh))".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh trinh ((cua phong) or (cuu phong)) cong dan ((than man) OR (tran manh))*.