Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
van hanh » van thanh, ban hanh, van anh
dat tren » dat trong, dua tren
tu sach » thu sach, su sach, te sach
ky canh » ky cach, ky danh, ky hanh
tac hoi » tao hoi, tay hoi, tac hai
va cham » va chat, va tham
luc van » luoc van, luu van, duc van
ky anh » ky danh, ly anh, ty anh
vi dat » voi dat, vi dai, va dat

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky canh) or (ky anh)) tac hoi. lieu va cham luc van hanh vi dat tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky canh) OR (ky anh)) tac hoi. lieu va cham luc van hanh vi dat tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky canh) or (ky anh)) tac hoi. lieu va cham luc van hanh vi dat tren*.