Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
hieu ve » hieu van
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sac ky)) tang ma hoa. ((hieu ve) or (hieu va)) cac duc va thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) tang ma hoa. ((hieu ve) OR (hieu va)) cac duc va thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) tang ma hoa. ((hieu ve) or (hieu va)) cac duc va thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) tang ma hoa. ((hieu ve) or (hieu va)) cac duc va thanh vi cua tre*.