Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thanh de » hanh de, thanh ve, thanh do
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
cau duc » cao duc, cau luc, chu duc
van cau » van dau, van hau, van chat
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
de cua » le cua, te cua, dieu cua

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 ((((nang ma) or (mang may))) or (nang x)) hoi. hieu van cau duc va thanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((((nang ma) OR (mang may))) OR (nang x)) hoi. hieu van cau duc va thanh de cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((((nang ma) or (mang may))) or (nang x)) hoi. hieu van cau duc va thanh de cua tre*.