Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cuu tre » cua tre, cau tren, cau treo
dao vat » dao van, tao vat, dao va
ca tren » cau tren, cu tren, la tren
hieu ve » hieu va, hieu van
ty hang » ly hang, thi hang, thu hang
cam tu » cam thu, nam tu, dam tu
va dao » ca dao
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty xang) or (ty hang)) xa hoi. hieu ve cam tu va dao vat ((cuu tre) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty xang) OR (ty hang)) xa hoi. hieu ve cam tu va dao vat ((cuu tre) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty xang) or (ty hang)) xa hoi. hieu ve cam tu va dao vat ((cuu tre) or (ca tren))*.