Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach chu » sach che, sach thu, sach thue
chu bang » thu bang, chuc nang, chu quang
qua cham » qua hai, qua cac, va cham
bang xa » lang xa, bang va, mang xa
hanh ly » khanh ly, hanh ky, hang ly
soc va » loc va, goc va, uoc va
doc va » duoc va, duc va, loc va
ly cua » le cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach chu bang xa hoi. hieu qua cham ((((soc va) OR (hoc va))) or (doc va)) hanh ly cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach chu bang xa hoi. hieu qua cham ((((soc va) OR (hoc va))) OR (doc va)) hanh ly cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach chu bang xa hoi. hieu qua cham ((((soc va) OR (hoc va))) or (doc va)) hanh ly cua tu".
• Adding a wildcard symbol may retrieve word variants: toc sach chu bang xa hoi. hieu qua cham ((((soc va) OR (hoc va))) or (doc va)) hanh ly cua tu*.