Perhaps you should try some spelling variations:
khanh van » thanh van, khanh vinh, hanh va
xa khanh » xa thanh, van khanh, dat khanh
van cua » vang cua, ban cua, dan cua
cao duc » dao duc, cao suc, giao duc
sach tu » sach thu, sach ty, sach uu
cao tuc » dao tuc, cao suc, cao toc
nang xa » nang x, lang xa, nang ma
cach tu » cach thuc
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach tu) or (cach tu)) nang xa hoi. hieu qua ((cao tuc) OR (cao duc)) xa khanh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (cach tu)) nang xa hoi. hieu qua ((cao tuc) OR (cao duc)) xa khanh van cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) or (cach tu)) nang xa hoi. hieu qua ((cao tuc) OR (cao duc)) xa khanh van cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (cach tu)) nang xa hoi. hieu qua ((cao tuc) OR (cao duc)) xa khanh van cua tre*.