Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang xay » dang van, van xay
quoc lan » quoc ban, nuoc luan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
anh hoc » sinh hoc, benh hoc, hinh hoc
lan anh » van anh, tuan anh
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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: ((thuoc sach) OR (tu sach)) y ((lang xa) OR (dang xay)) hoi. hieu va cam quoc lan anh hoc cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (tu sach)) y ((lang xa) OR (dang xay)) hoi. hieu va cam quoc lan anh hoc cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (tu sach)) y ((lang xa) OR (dang xay)) hoi. hieu va cam quoc lan anh hoc cua tre*.