Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
nhung cong » thong cong, hang cong, nhung don
dung cong » dung trong
hien anh » hien hanh, thien anh, dien anh
trinh va » trinh van, trinh vat, trinh ve
than cau » toan cau, phan cau, than cap
toan cao » toan ban, toan tap

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

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