Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu nang » thu hang, thu bang, tho nang
thi nang » thi cong, ki nang, thi hanh
hanh dai » hanh tai, hanh dao, vanh dai
qua cac » cua cac
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet

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 ((thu nang) or (thi nang)) xa hoi. hieu qua cac duc va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((thu nang) OR (thi nang)) xa hoi. hieu qua cac duc va hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((thu nang) or (thi nang)) xa hoi. hieu qua cac duc va hanh dai cua tre*.