Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
cac cuoc » cac nuoc, ca cuoc, cac quoc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
cac cua » cach cua, cac qua, ca cua
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 van ((cac cuoc) or (cac cua)) ban thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. hieu van ((cac cuoc) OR (cac cua)) ban thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xa hoi. hieu van ((cac cuoc) or (cac cua)) ban thanh dai cua tre*.