Perhaps you should try some spelling variations:
voi doanh » von doanh, tri doanh, hoa doanh
thu sach » tu sach, thuat sach, thuoc sach
va doanh » van doanh, vay doanh, va danh
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
cam luc » cam xuc, cau luc
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca 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 van)) cam luc ((va doanh) or (voi doanh)) va 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 van)) cam luc ((va doanh) OR (voi doanh)) va 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 van)) cam luc ((va doanh) or (voi doanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu ve) OR (hieu van)) cam luc ((va doanh) or (voi doanh)) va cua tre*.