Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu tang » thu trang, thu thang, thu hang
cham luc » cham soc, nhan luc, chat lua
cham cuu » cap cuu, chat cua
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
van hoe » van hoc, van hieu, van hien
hanh va » hang va, hanh vi
va cua » va chua, via cua, ca cua
cua tu » cua tuc, cua su, cua cu

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 tang ((van hoe) or (van hoa)). hieu qua ((cham luc) OR (cham cuu)) van hanh va cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu tang ((van hoe) OR (van hoa)). hieu qua ((cham luc) OR (cham cuu)) van hanh va cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu tang ((van hoe) or (van hoa)). hieu qua ((cham luc) OR (cham cuu)) van hanh va cua tu".
• Adding a wildcard symbol may retrieve word variants: so sach thu tang ((van hoe) or (van hoa)). hieu qua ((cham luc) OR (cham cuu)) van hanh va cua tu*.