Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
duc ban » duc tan, dua ban, duc man
duc van » duc va, duc tan, duc manh
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
vi cua » vai cua, di cua
cua te » cua tu

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: tu sac ky nang cau hoi. ((hieu van) OR (hieu va)) cham ((duc ban) OR (duc van)) hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang cau hoi. ((hieu van) or (hieu va)) cham ((duc ban) OR (duc van)) hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang cau hoi. ((hieu van) or (hieu va)) cham ((duc ban) OR (duc van)) hanh vi cua te*.