Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh vai » hanh vi, hanh va, hanh tai
hai trac » hoi trac, khai thac, thai tran
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
van hai » van ha, van chat, van hanh
mang xa » lang xa, mang may, mang cua
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
trac va » truc va, tac va, thac va
nang ma » tang ma, sang ma, nang cao
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky ((((mang xa) or (dang xay))) or (nang ma)) hoi. hieu van hai trac va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((((mang xa) OR (dang xay))) OR (nang ma)) hoi. hieu van hai trac va hanh vai cua tre*.