Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cac xuc » cam xuc, cac nuoc, chat xuc
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
xuc va » duc va, tuc va, luc va
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho

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 (toc sach)) ky nang x hoi. hieu ve cac xuc va hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x hoi. hieu ve cac xuc va hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang x hoi. hieu ve cac xuc va hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. hieu ve cac xuc va hanh vi ((cua tre) OR (cuu tre))*.