Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
doc hieu » toc thieu, hoc thieu, hoc hien
trinh va » trinh van, trinh vat, trinh ve
cong san » cong tac
than cau » than cap, thanh chau, thanh mau
toan cau » toan cao, toan ban, toan tap
phan cau » phan dau, phan cac, phan tu

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 cach - hanh trinh va nhung cong san ((((than cau) OR (toan cau))) or (phan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu cach - hanh trinh va nhung cong san ((((than cau) OR (toan cau))) OR (phan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu cach - hanh trinh va nhung cong san ((((than cau) OR (toan cau))) or (phan cau))".
• Adding a wildcard symbol may retrieve word variants: doc hieu cach - hanh trinh va nhung cong san ((((than cau) OR (toan cau))) or (phan cau))*.