Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hieu va » lieu va
dau duc » dao duc, dang duc, dau nuoc
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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 x hoi. ((hieu va) OR (hieu qua)) dau duc van hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((hieu va) OR (hieu qua)) dau duc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. ((hieu va) OR (hieu qua)) dau duc van hanh vi cua tre*.