Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
sach ty » sach tu, sach thu, xach tay
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, tuc xa, duc va
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sach y)) nang x hoi. hieu van cam ((tuc va) or (truc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang x hoi. hieu van cam ((tuc va) OR (truc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang x hoi. hieu van cam ((tuc va) or (truc va)) hanh vi cua tre*.