Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
chat xuc » chat huu, cam xuc, chao xu
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, cac cuoc
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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

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