Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
canh tinh » hanh tinh, manh tinh, canh tranh
tong cong » trong cong, cong cong, dung cong
hoc hieu » hoc thieu, hoc hien, doc hieu
tinh van » trinh van, dinh van, tinh va
phan cau » phan dau, phan tu, phan lap
phan cac » nhan cach, phan dau, phan lap

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: hoc hieu manh - canh tinh van ((thong thong) OR (tong cong)) doan ((phan cau) OR (phan cac))~.
• Adding a wildcard symbol may retrieve word variants: hoc hieu manh - canh tinh van ((thong thong) or (tong cong)) doan ((phan cau) or (phan cac))*.