Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach tay » xach tay, sach hay, sach nay
thuc day » thuc dan, thuc vat
vat cuu » vat cua
dan vat » dang vat, van vat, dan va
thuc va » thuc vat, thuc dan
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
lang ha » long ha
lang xa » dang xay, lang van
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tay ((lang xa) or (lang ha)) hoi. hieu va nam ((thuc va) OR (thuc day)) dan vat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tay ((lang xa) OR (lang ha)) hoi. hieu va nam ((thuc va) OR (thuc day)) dan vat cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tay ((lang xa) or (lang ha)) hoi. hieu va nam ((thuc va) OR (thuc day)) dan vat cuu tre*".