Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
ban danh » ban doanh, ban dan, van danh
lang van » dang van, tang van, hoang van
hieu ve » hieu va, hieu van
cau cua » cau qua, ca cua, cu cua
sach ky » sac ky, sach y, sach ty
van hoc » van hoa
ky lang » ky nang, ky dang, ky tang
tu sach » thu sach, su sach, te sach
ve cau » ke cau, va cau, ve cac

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 ky lang van hoc. hieu ve cau cua ((ban danh) OR (ban hanh)) vai ((cau tren) OR (su triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang van hoc. hieu ve cau cua ((ban danh) OR (ban hanh)) vai ((cau tren) or (su triet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang van hoc. hieu ve cau cua ((ban danh) OR (ban hanh)) vai ((cau tren) or (su triet))*.