Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
tru nang » tra nang, tri nang, truc nano
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
tu nang » tu nong, tu nano, tu lang
cua tre » cua te, cuu tre, cua triet
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: ((te sach) OR (toc sach)) ((tu nang) or (tru nang)) xa hoi. hieu va cham duc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((tu nang) OR (tru nang)) xa hoi. hieu va cham duc va hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ((tu nang) or (tru nang)) xa hoi. hieu va cham duc va hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ((tu nang) or (tru nang)) xa hoi. hieu va cham duc va hanh di cua tre*.