Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
dua tren » dung tren
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sach ly » sach y, sach lo, sach ty
va hanh » van hanh, va thanh, va danh
cu tren » tu tren
va cham » va chat, va tham
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: thu sach ly ((nang ma) or (tang ma)) hoi. lieu va cham luc va hanh vi ((cu tren) OR (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ly ((nang ma) OR (tang ma)) hoi. lieu va cham luc va hanh vi ((cu tren) OR (dua tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ly ((nang ma) or (tang ma)) hoi. lieu va cham luc va hanh vi ((cu tren) OR (dua tren))".
• Adding a wildcard symbol may retrieve word variants: thu sach ly ((nang ma) or (tang ma)) hoi. lieu va cham luc va hanh vi ((cu tren) OR (dua tren))*.