Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
ban hanh » ban hang
lang van » tang van, hoang van, giang van
dang van » hoang van, hang va
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
cau cua » cau qua, ca cua, cu cua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve cau » ke cau, va cau, ve cac

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