Perhaps you should try some spelling variations:
ban hang » ngan hang
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
van dam » van nam, van dao, van dau
va danh » va dinh, va dan, va hanh
van am » van nam, van lam, van ai
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty nang x hoi. hieu ((van am) OR (van dam)) thuc ((va danh) or (ban hang)) mai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu ((van am) OR (van dam)) thuc ((va danh) OR (ban hang)) mai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu ((van am) OR (van dam)) thuc ((va danh) or (ban hang)) mai va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu ((van am) OR (van dam)) thuc ((va danh) or (ban hang)) mai va triet*.