Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
quoc ban » quoc bao, quoc lan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
tu sach » su sach, te sach, tu cach
anh vai » anh bai, anh van, anh tai
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
anh va » hanh va
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: ((tu sach) OR (thu sach)) ky lang xa hoi. lieu va cam quoc ban ((anh vai) OR (anh va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky lang xa hoi. lieu va cam quoc ban ((anh vai) OR (anh va)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky lang xa hoi. lieu va cam quoc ban ((anh vai) OR (anh va)) cua tre*.