Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hoc thieu » toc thieu, hoc hien
doc hieu » toc thieu, hoc hien
trinh ha » trinh han, trinh hoa, trinh nha
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
than cau » toan cau, phan cau, than cap
ha tong » han tong, ha dong, ha tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (hoc thieu)) xanh - hanh trinh ha tong ((cong dan) OR (cong tan)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) xanh - hanh trinh ha tong ((cong dan) OR (cong tan)) than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (hoc thieu)) xanh - hanh trinh ha tong ((cong dan) OR (cong tan)) than cau".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc thieu)) xanh - hanh trinh ha tong ((cong dan) OR (cong tan)) than cau*.