Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
cac tuc » cac toc, cac tu, cac nuoc
cac tac » cac toc, cac bac, cac dac
dan thi » dang thi, tran thi, dinh thi
thi cua » thai cua, thi cuc, tri cua
cua tre » cua te, cuu tre, cua triet
y nang » ly nang, v nang, may nang
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 ((y nang) OR (ky nang)) xa hoi. hieu qua ((cac tuc) or (cac tac)) va dan thi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ky nang)) xa hoi. hieu qua ((cac tuc) OR (cac tac)) va dan thi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) xa hoi. hieu qua ((cac tuc) or (cac tac)) va dan thi cua tre*".