Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham luc » cham soc, nhan luc, cham cuu
van hanh » van thanh, ban hanh, van anh
thu sach » thuat sach, thuoc sach, thu hoach
vuc lang » vuc nang, va lang, duc long
luc van » luoc van, luu van, duc van
tu sach » su sach, te sach, tu cach
lang xa » lang ha, dang xay, lang van
vi su » va su, ve su, oi su
ki su » ky su

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) or (thu sach)) vuc lang xa hoi. hieu qua cham luc van hanh ((vi su) or (ki su)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) vuc lang xa hoi. hieu qua cham luc van hanh ((vi su) OR (ki su)) viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) vuc lang xa hoi. hieu qua cham luc van hanh ((vi su) or (ki su)) viet*.