Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac tuc » cac tu, cac nuoc, cac cuoc
cac toc » cac toi, cac nuoc, cac thoi
cac tac » cac bac, cac dac, cac tai
dan thi » dang thi, tran thi, dinh thi
thi cua » thai cua, thi cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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

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