Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cac thuc » cach thuc, cac thu, can thuc
su sach » so sach, vu sach
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
ly vang » ly hang, ly van, ly quang
ly nang » ky nang, ly hang, ly quang
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 ((ly nang) or (ly vang)) xa hoi. ((hieu ve) OR (hieu van)) cac thuc va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly nang) OR (ly vang)) xa hoi. ((hieu ve) OR (hieu van)) cac thuc va danh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly nang) or (ly vang)) xa hoi. ((hieu ve) OR (hieu van)) cac thuc va danh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ly nang) or (ly vang)) xa hoi. ((hieu ve) OR (hieu van)) cac thuc va danh vi cua tre*.