Perhaps you should try some spelling variations:
cuon sach » duong sach, cuoc cach, nuoc sach
co sach » bo sach, hoc sach
cao duc » dao duc, cao suc, giao duc
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
hieu va » lieu va, hieu qua
di cua » dai cua, doi cua, de 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: ((co sach) or (cuon sach)) ty nang xa hoi. ((hieu ve) or (hieu va)) cao duc va hang di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (cuon sach)) ty nang xa hoi. ((hieu ve) OR (hieu va)) cao duc va hang di cua tu.
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (cuon sach)) ty nang xa hoi. ((hieu ve) or (hieu va)) cao duc va hang di cua tu*.