Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va triet » va trien, ve triet, cua triet
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
sach lo » sach dao, sach doi, sach hoi
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
lo nang » ho nang, ly nang, loai nang
ma hoi » mai hoi, xa hoi, ma hoa
thiet » thieu

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