Perhaps you should try some spelling variations:
manh trung » manh tung, thanh trung, manh hung
nhung cong » dung cong, thong cong, hang cong
trung cap » truong cao, trung tam
cap nhung » cam nhung, vap nhung, dap nhung
hieu cac » hieu luc, hieu van, vien cac
cong ban » cong bang, cong san, cong tan
khan cap » khan ap, khoan cam, phan cac
than cap » thanh lap, thanh cac, than cua
hieu va » lieu va, hieu qua

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 cac) or (hieu va)) - manh trung cap nhung cong ban ((khan cap) OR (than cap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu cac) OR (hieu va)) - manh trung cap nhung cong ban ((khan cap) OR (than cap))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu cac) or (hieu va)) - manh trung cap nhung cong ban ((khan cap) OR (than cap))*".