Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham luc » cham soc, nhan luc, cham cuu
su sach » so sach, vu sach
nang ro » nang co, nang ho, nang ra
va hanh » van hanh, va thanh, va danh
nang o » nang co, nang ho, nang x
luc va » duc va, tuc va, loc va
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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: su sach y ((nang o) OR (nang ro)) hoi. hieu qua cham luc va hanh ((vi cua) OR (di cua)) tre~.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang o) or (nang ro)) hoi. hieu qua cham luc va hanh ((vi cua) or (di cua)) tre*.