Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nam thuc » nam thuoc, am thuc, nam thu
va triet » va thiet, va trien, ve triet
van hang » van khang, van hoang, van thang
thuc van » thuc vat, thuc dan, thuc va
sach thu » sach thue, sach thieu, sach tham
hang di » hang doi, hang vi, hang dien
so sach » so sanh, bo sach, co sach
hieu he » hieu ve, hiem he, hieu le
nang ma » tang ma, sang ma, mang may
he nam » ha nam, nghe nam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu ((nang ma) OR (nang cao)) hoi. hieu he nam thuc van hang di ((va triet) OR (su triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu ((nang ma) OR (nang cao)) hoi. hieu he nam thuc van hang di ((va triet) or (su triet))~".
• Adding a wildcard symbol may retrieve word variants: so sach thu ((nang ma) OR (nang cao)) hoi. hieu he nam thuc van hang di ((va triet) or (su triet))*.