Perhaps you should try some spelling variations:
su sach » so sach, vu sach
van anh » van thanh, tuan anh, van minh
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
ly nang » ky nang, ly hang, ly vang
y nang » ky nang, v nang, may nang
anh vi » hanh vi, anh va, anh ve
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) OR (ly nang)) xa hoi. ((hieu ve) or (hieu va)) cao duc van anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly nang)) xa hoi. ((hieu ve) OR (hieu va)) cao duc van anh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) OR (ly nang)) xa hoi. ((hieu ve) or (hieu va)) cao duc van anh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) OR (ly nang)) xa hoi. ((hieu ve) or (hieu va)) cao duc van anh vi cua tre*.