Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
tay lang » tai lang, tay tang, tay quang
tinh hai » tinh thai, tinh chat, trinh han
tay dung » xay dung, tac dung, tay nung
cay phoi » cap phoi, tay hoi, cay cho
hai cua » thai cua, dai cua, hoi cua
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nam tu » nam thu

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)) cay phoi. hieu ve ((nam tu) OR (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)) cay phoi. hieu ve ((nam tu) OR (nam thuc)) va tinh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tay lang) or (tay dung)) cay phoi. hieu ve ((nam tu) OR (nam thuc)) va tinh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((tay lang) or (tay dung)) cay phoi. hieu ve ((nam tu) OR (nam thuc)) va tinh hai cua tre*.