Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
chat luc » chat xuc, chat lua, nhan luc
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
cua viet » ca viet, hoa viet, cua vat
hieu ve » hieu va, hieu van
ty nang » ky nang, ty xang, ty hang
so sach » so sanh, bo sach, co sach
lai cua » dai cua, hai cua, lai chau
ve chat » va chat, van chat

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) or (so sach)) ty nang x ho. hieu ve chat luc ((van hanh) OR (ban hanh)) lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (so sach)) ty nang x ho. hieu ve chat luc ((van hanh) OR (ban hanh)) lai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (so sach)) ty nang x ho. hieu ve chat luc ((van hanh) OR (ban hanh)) lai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (so sach)) ty nang x ho. hieu ve chat luc ((van hanh) OR (ban hanh)) lai cua viet*.