Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nang xa » lang xa, nang ma, mang xa
sach ty » sach y, sach tu, sach thu
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, duc va
vi cua » vai cua, di cua

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: thu sach ty ((nang xa) OR (nang x)) hoi. hieu van cam ((tuc va) OR (tuc xa)) hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang xa) or (nang x)) hoi. hieu van cam ((tuc va) or (tuc xa)) hanh vi cua tre*.