Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
van hanh » van thanh, ban hanh, van anh
dua tren » dung tren
nang ma » tang ma, sang ma, nang cao
va cham » va chat, va tham
luc van » luoc van, luu van, duc van
cu tren » tu tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((nang x) or (nang ma)) hoi. lieu va cham luc van hanh vi ((cu tren) OR (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang x) OR (nang ma)) hoi. lieu va cham luc van hanh vi ((cu tren) OR (dua tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y ((nang x) or (nang ma)) hoi. lieu va cham luc van hanh vi ((cu tren) OR (dua tren))*".