Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
quoc ban » quoc bao, quoc lan, quoc quan
manh hai » lanh hai, minh hai, thanh hai
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
van lam » van nam
hai cua » thai cua, dai cua, hoi 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: thu sach ky dang xa hoi. hieu van lam ((quoc ban) or (duc tan)) manh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dang xa hoi. hieu van lam ((quoc ban) OR (duc tan)) manh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky dang xa hoi. hieu van lam ((quoc ban) or (duc tan)) manh hai cua tre*.