Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
nang xa » lang xa, nang ma, mang xa
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
cua tre » cua te, cuu tre, cua triet
te sai » te tai, te bai, te lai
sai ky » sac ky
vi cua » vai cua, di cua

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

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