Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach
vu sach » vu bach, vu khach
dinh le » dinh ve, dinh ly, dinh ket
va dinh » van dinh, va kinh, va tinh
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
le cua » ly cua
cua te » cua tu
ma hoi » mai hoi, ma hoa, me hoi
y nang » ky nang, ly nang, v nang

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) or (vu sach)) y nang ((ma hoi) OR (xa hoi)). hieu van cac duc va dinh le cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) y nang ((ma hoi) OR (xa hoi)). hieu van cac duc va dinh le cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) y nang ((ma hoi) OR (xa hoi)). hieu van cac duc va dinh le cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) y nang ((ma hoi) OR (xa hoi)). hieu van cac duc va dinh le cua te*.