Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
hieu va » lieu va, hieu qua
va chao » va cao, va chat, va cham
van anh » van thanh, van minh
cua tre » cua te, cuu tre, cua triet
ty ang » ty xang, ty hang, ty anh
ang xa » lang xa, mang xa, dang xay
vi cua » vai cua, di cua
tuan » quan, tran, luan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) OR (hoc sach)) ty ang xa hoi. hieu va chao xu ((van anh) or (tuan anh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) ty ang xa hoi. hieu va chao xu ((van anh) OR (tuan anh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (hoc sach)) ty ang xa hoi. hieu va chao xu ((van anh) or (tuan anh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (hoc sach)) ty ang xa hoi. hieu va chao xu ((van anh) or (tuan anh)) vi cua tre*.