Perhaps you should try some spelling variations:
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
ho chiet » ho chieu, ho thiet, hoa thiet
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan cau » toan cao, toan ban, toan tap
tinh va » tich va, trinh van, trinh vat

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

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