Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
hanh va » hang va, hanh vi
va hieu » van hieu, va dieu, va hien
sach ly » sach y, sach lo, sach hay
hieu ve » hieu va, hieu van
cao hoi » cau hoi, co hoi, cao hoc
sach ty » sach y, sach tu, sach thu
ve nam » he nam, va nam, le nam

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