Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
duc van » duc va, duc manh, duc phan
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
di cua » dai cua, doi cua, de cua
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach tu)) nang o hoi. hieu van nam ((duc van) or (duc tan)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) nang o hoi. hieu van nam ((duc van) OR (duc tan)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach tu)) nang o hoi. hieu van nam ((duc van) or (duc tan)) hanh di cua tre*.