Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
va hanh » van hanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
di cua » dai cua, doi cua, de 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 va) OR (lieu va)) cam xuc ((va hanh) or (va thanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang xa hoi. ((hieu va) OR (lieu va)) cam xuc ((va hanh) OR (va thanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. ((hieu va) OR (lieu va)) cam xuc ((va hanh) or (va thanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. ((hieu va) OR (lieu va)) cam xuc ((va hanh) or (va thanh)) di cua tre*.