Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
cac cuoc » cac nuoc, ca cuoc, cac quoc
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
cac cua » cach cua, cac qua, ca cua
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky dang xa hoi. ((hieu va) or (hieu van)) ((cac cuoc) or (cac cua)) ban hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. ((hieu va) OR (hieu van)) ((cac cuoc) OR (cac cua)) ban hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xa hoi. ((hieu va) or (hieu van)) ((cac cuoc) or (cac cua)) ban hanh vai cua tre*.