Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
cham luc » cham soc, nhan luc, cham cuu
van hieu » cao hieu
sach thu » sach thieu, sach tham, cach thuc
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
va cham » va chat, va tham
vi cua » vai cua, di cua
luc va » duc va, tuc va, loc va
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach thu) or (sach thue)) tang ((van hieu) or (van hoa)). hieu va cham luc va hanh vi cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach thu) OR (sach thue)) tang ((van hieu) OR (van hoa)). hieu va cham luc va hanh vi cua cu.
• Adding a wildcard symbol may retrieve word variants: so ((sach thu) or (sach thue)) tang ((van hieu) or (van hoa)). hieu va cham luc va hanh vi cua cu*.