Perhaps you should try some spelling variations:
dan doan » dan toan, tan doan, chan doan
van doan » van doanh, van toan, van hoan
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ca viet » va viet, co viet, hoa viet
va nam » van nam, ha nam, va nay
he nam » ha nam, nghe nam
van ca » van cau, van cua, dan ca
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu ((va nam) OR (he nam)) thuc ((dan doan) OR (van doan)) van ca viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu ((va nam) or (he nam)) thuc ((dan doan) OR (van doan)) van ca viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu ((va nam) or (he nam)) thuc ((dan doan) OR (van doan)) van ca viet*.