Perhaps you should try some spelling variations:
tay quang » tac quang, tai quang, vay quang
tao quang » dao quang, hao quang, lao quang
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cua tre » cuu tre, cua triet, dua tren
dan vai » dan va, dan tai, dan vat
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
va dan » ca dan, va dao, va dau
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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 quang) or (tao quang)) ma hoi. hieu va nam thuc va dan vai ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((tay quang) OR (tao quang)) ma hoi. hieu va nam thuc va dan vai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((tay quang) or (tao quang)) ma hoi. hieu va nam thuc va dan vai ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach ((tay quang) or (tao quang)) ma hoi. hieu va nam thuc va dan vai ((cua tre) OR (cua te))*.