Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
hieu vu » hieu ve, hieu su, dieu vu
vi cua » vai cua, di cua
va don » va dong, va doc, va do
luc va » duc va, tuc va, loc va
cua te » cua tu
sach v » sach va, sach 2, sach vay

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 ((sach v) OR (sach y)) nang xa hoi. ((hieu vu) OR (hieu va)) cham luc va don vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach v) or (sach y)) nang xa hoi. ((hieu vu) OR (hieu va)) cham luc va don vi cua te~".
• Adding a wildcard symbol may retrieve word variants: te ((sach v) or (sach y)) nang xa hoi. ((hieu vu) OR (hieu va)) cham luc va don vi cua te*.