Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ban doanh » van doanh, san doanh, ban danh
cham cuu » cap cuu, chat cua
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
ve cham » va cham, ve chat, vu cham
sach ky » sac ky, sach y, sach ty
van hoc » van hoa
van hoi » van hoa, van hoe, van loi
ky lang » ky nang, ky dang, ky tang
hieu ve » hieu va, hieu van
vi cua » vai cua, di cua

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 ky lang ((van hoi) OR (van hoc)). hieu ve cham cuu ((ban doanh) or (ban hanh)) vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((van hoi) OR (van hoc)). hieu ve cham cuu ((ban doanh) OR (ban hanh)) vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((van hoi) OR (van hoc)). hieu ve cham cuu ((ban doanh) or (ban hanh)) vi cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((van hoi) OR (van hoc)). hieu ve cham cuu ((ban doanh) or (ban hanh)) vi cua triet*.