Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
phan do » phan bo, phan co, phan mo
ke phan » ve phan, kenh phan, ke thang
tu sach » thu sach, su sach, te sach
lang ha » long ha
lang xa » dang xay, lang van
hieu ke » hieu kem, chieu ke, hieu ky
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 xa) OR (lang ha)) hoi. hieu ke phan do ((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 xa) OR (lang ha)) hoi. hieu ke phan do ((van hanh) or (ban hanh)) vi su triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((lang xa) OR (lang ha)) hoi. hieu ke phan do ((van hanh) or (ban hanh)) vi su triet*.