Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
chat cuu » chat huu, chat cua, cham cuu
sach tru » sach truc, sach thu, sach tu
van chat » cao chat
tru nang » tra nang, tri nang, truc nano
cuu ban » cuu van, cua ban, cuu san
hanh di » hanh de, hang di, danh di
cua tre » cua te, cuu tre, cua triet

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 tru nang ((ma hoa) or (xa hoi)). hieu van chat cuu ban ((hanh di) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach tru nang ((ma hoa) OR (xa hoi)). hieu van chat cuu ban ((hanh di) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach tru nang ((ma hoa) or (xa hoi)). hieu van chat cuu ban ((hanh di) or (hanh vi)) cua tre*.