Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
thuc day » thuc dan, thuc vat
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
thuc va » thuc vat, thuc dan
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
dan tai » van tai, dan thi, han tai
cuu tre » cua tre, cau treo
va nam » van nam, ha nam, va nay

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: doc sach ty lang xa hoi. hieu va nam ((thuc va) OR (thuc day)) dan tai ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty lang xa hoi. hieu va nam ((thuc va) or (thuc day)) dan tai ((cuu tre) OR (cau tren))~".
• Adding a wildcard symbol may retrieve word variants: doc sach ty lang xa hoi. hieu va nam ((thuc va) or (thuc day)) dan tai ((cuu tre) OR (cau tren))*.