Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
thuc va » thuc vat, thuc day
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua

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