Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cham luc » cham soc, nhan luc, cham cuu
dua tren » dung tren
nang ma » tang ma, sang ma, nang cao
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cu tren » tu tren
luc va » duc va, tuc va, loc va

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

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