Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
van dau » van dao, phan dau
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
dai va » mai va
van am » van nam, van lam, van dam
x hoi » xa hoi, o hoi, x ho

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) OR (sach ty)) nang x hoi. hieu ((van am) or (van dau)) thuc va hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang x hoi. hieu ((van am) OR (van dau)) thuc va hanh dai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang x hoi. hieu ((van am) or (van dau)) thuc va hanh dai va triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang x hoi. hieu ((van am) or (van dau)) thuc va hanh dai va triet*.