Perhaps you should try some spelling variations:
dieu cua » dieu tra
van hanh » van thanh, ban hanh, van anh
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cac luc » coc luc, cac nuoc, cac cuoc
cau luc » cau truc, cau phuc
te cua » tue cua, le cua, de cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa

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: te sac ky nang ma hoi. hieu ve ((cac luc) OR (cau luc)) van hanh ((dieu cua) OR (te cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky nang ma hoi. hieu ve ((cac luc) OR (cau luc)) van hanh ((dieu cua) or (te cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: te sac ky nang ma hoi. hieu ve ((cac luc) OR (cau luc)) van hanh ((dieu cua) or (te cua)) tre*.