Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hanh hai » thanh hai, nhanh hai, hang hai
te sach » toc sach
hai cua » thai cua, dai cua, hoi cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
ca xuc » chat xuc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (doc sach)) ty nang xa hoi. hieu qua ((ca xuc) OR (cam xuc)) va hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ty nang xa hoi. hieu qua ((ca xuc) OR (cam xuc)) va hanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (doc sach)) ty nang xa hoi. hieu qua ((ca xuc) OR (cam xuc)) va hanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ty nang xa hoi. hieu qua ((ca xuc) OR (cam xuc)) va hanh hai cua tre*.