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
cong dan » cong san, cong tan, huong dan
chan man » than man, chan doan, chan dang
chan nan » chan nhan, chang nang, chan doan

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 ((chan man) OR (chan nan))~.
• 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 ((chan man) OR (chan nan)).
• 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 ((chan man) OR (chan nan))".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh trinh ((cua phong) or (cuu phong)) cong dan ((chan man) OR (chan nan))*.