Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
hieu ha » hieu hoa, hieu va, hieu ca
ty lang » tay lang, ty xang, ty hang
thuc va » thuc vat, thuc dan, thuc day
sach ty » sach y, sach tu, sach thu
dan vai » dan tai, dan vat, dang van
den vai » den va, den vay, den vi
dan va » doan va, dan ca, ban va

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

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