Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tinh hai » tinh thai, tinh chat, trinh han
nam thuc » nam thuoc, am thuc, nam thu
tay lang » tai lang, tay tang, tay quang
tay dung » xay dung, tac dung, tay nung
xay hoi » xa hoi, tay hoi, cay phoi
hieu he » hieu ve, hiem he, hieu le
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
he nam » ha nam, nghe nam

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 ((tay lang) or (tay dung)) xay hoi. hieu he nam thuc va tinh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tay lang) OR (tay dung)) xay hoi. hieu he nam thuc va tinh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((tay lang) or (tay dung)) xay hoi. hieu he nam thuc va tinh hai cua tre*.