Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cua tre » cua te, cua triet, dua tren
danh di » danh du, xanh di, danh dien
va danh » va dinh, va dan, va hanh
qua cac » cua cac
cac luc » cau luc, coc luc, cac nuoc
cuu tre » cau tren, cau treo
y nang » ky nang, ly nang, may nang
luc va » duc va, tuc va, loc va
v nang » va nang, vu nang, van nang

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) OR (v nang)) xa hoi. hieu qua cac luc va danh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y nang) OR (v nang)) xa hoi. hieu qua cac luc va danh di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y nang) OR (v nang)) xa hoi. hieu qua cac luc va danh di ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y nang) OR (v nang)) xa hoi. hieu qua cac luc va danh di ((cua tre) or (cuu tre))*.