Perhaps you should try some spelling variations:
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
hieu ke » hieu kem, chieu ke, hieu ky
ke phan » ve phan, kenh phan, ke thang
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land
vi su » va su, ve su, ki su

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: tu sach ((y lang) OR (_ lang)) xa hoi. hieu ke phan bo ((van hanh) OR (ban hanh)) vi su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) OR (_ lang)) xa hoi. hieu ke phan bo ((van hanh) or (ban hanh)) vi su triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) OR (_ lang)) xa hoi. hieu ke phan bo ((van hanh) or (ban hanh)) vi su triet*.