Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
ve cac » va cac, vien cac
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang ((ma hoa) OR (((mai hoi) OR (lai hoi)))). hieu ve cac duc van hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang ((ma hoa) or (((mai hoi) OR (lai hoi)))). hieu ve cac duc van hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach v nang ((ma hoa) or (((mai hoi) OR (lai hoi)))). hieu ve cac duc van hanh vi cua tre*.