Perhaps you should try some spelling variations:
tay quang » tac quang, tai quang, tao quang
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
tay lang » tai lang, tay tang, tham lang
hieu va » hieu qua
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
va dan » ca dan, va dao, va dau

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