Perhaps you should try some spelling variations:
dao duoc » tao duoc, dao duc, da duoc
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
duoc va » nuoc va, duc va, duoc ma
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
ma hoi » xa hoi, ma hoa, me hoi
ve dao » de dao, va dao, ve bao
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky nang ((ma hoi) or (mai hoi)). hieu ve dao duoc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky nang ((ma hoi) OR (mai hoi)). hieu ve dao duoc va hanh di cua tre*.