Perhaps you should try some spelling variations:
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
cac thu » cach thuc, cac thoi
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ly vang » ly hang, ly van, ly quang
ly nang » ky nang, ly hang, ly quang
ve cac » va cac, vien cac
thu va » thuc va, thue va, tu va
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, 5 hoi

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