Perhaps you should try some spelling variations:
chet duoc » che duoc, cho duoc, che quoc
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
duoc van » duoc va, duc van, duoc ban
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
bai cua » ban cua, bai ca, hai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chet duoc van thanh ((bai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chet duoc van thanh ((bai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chet duoc van thanh ((bai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu ve) OR (hieu va)) chet duoc van thanh ((bai cua) or (dai cua)) tre*.