Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
nhan luc » nang luc
cham luc » cham soc, cham cuu, chat lua
luu tre » luu tru, cuu tre, luy tre
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
sac ky » cac ky, sai ky
vi luu » vi lua
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky ((nang xa) or (nang ma)) hoi. hieu ve ((cham luc) OR (nhan luc)) van hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (nang ma)) hoi. hieu ve ((cham luc) OR (nhan luc)) van hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((nang xa) or (nang ma)) hoi. hieu ve ((cham luc) OR (nhan luc)) van hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (nang ma)) hoi. hieu ve ((cham luc) OR (nhan luc)) van hanh vi luu tre*.