Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
gian lan » gian lang, gian dan, giang van
lan cua » lang cua, ban cua, lai cua
va gian » va gianh, van gian, va giai
cao duc » dao duc, cao suc, giao duc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu

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: te ((sach ky) OR (sach ty)) nang xa hoi. ((hieu ve) OR (hieu van)) cao duc va gian lan cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach ty)) nang xa hoi. ((hieu ve) or (hieu van)) cao duc va gian lan cua tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach ty)) nang xa hoi. ((hieu ve) or (hieu van)) cao duc va gian lan cua tre*.