Perhaps you should try some spelling variations:
su triet » su viet, ve triet
thanh vi » hanh vi, thanh va, thanh ve
xa thanh » va thanh, ha thanh, ta thanh
tu sach » thu sach, su sach, te sach
cac dac » cac dan, cac dai, cac bac
su tien » su kien, su hien, tu tieng
hieu ve » hieu va, hieu van
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
dac xa » tac xa, cac xa, dan xa
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai

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 ((ty nang) OR (ty hang)) o hai. hieu ve cac dac xa thanh vi ((su triet) or (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) o hai. hieu ve cac dac xa thanh vi ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty hang)) o hai. hieu ve cac dac xa thanh vi ((su triet) or (su tien))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty hang)) o hai. hieu ve cac dac xa thanh vi ((su triet) or (su tien))*.