Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
cac thuc » cach thuc, cac thu, can thuc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, 5 hoi
o hoi » co hoi, o hoc, o hai

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: su sach y nang ((((x hoi) OR (o hoi))) OR (x ho)). hieu ve cac thuc vat hanh di cua tre~.
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((((x hoi) or (o hoi))) or (x ho)). hieu ve cac thuc vat hanh di cua tre*.