Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach kho » bach khoa, sach nha, sach kem
su triet » su viet, ve triet
sach dao » lanh dao
hanh vai » hanh vi, hanh va, hanh tai
vat hanh » vat thanh, van hanh, va hanh
thu vat » thuc vat, thu va, thuat vat
tang ha » lang ha, tang ma, trung ha
su tien » su kien, su hien, tu tieng
ha doi » hoa doi, hat doi, ha noi

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 kho) or (sach dao)) tang ha doi. hieu van nam thu vat hanh vai ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kho) OR (sach dao)) tang ha doi. hieu van nam thu vat hanh vai ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach kho) or (sach dao)) tang ha doi. hieu van nam thu vat hanh vai ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach kho) or (sach dao)) tang ha doi. hieu van nam thu vat hanh vai ((su triet) OR (su tien))*.