Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
hoc hieu » hoc thieu, hoc hien, doc hieu
cong san » cong tac
phan cau » phan dau, phan cac, phan lap
tung ca » trung ca, tang ca, hung ca
cung ca » cung cap, cung cua, cung cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu cach - thanh ((tung ca) OR (cung ca)) nhung cong san ((phan cau) or (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu cach - thanh ((tung ca) OR (cung ca)) nhung cong san ((phan cau) OR (phan tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu cach - thanh ((tung ca) OR (cung ca)) nhung cong san ((phan cau) or (phan tu))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu cach - thanh ((tung ca) OR (cung ca)) nhung cong san ((phan cau) or (phan tu))*.