Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
toc sach » hoc sach, doc sach, thuoc sach
vanh dai » van dai, vanh tai, lanh dao
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
ve cham » va cham, ve chat, vu cham
va vanh » va van, va danh, va hanh
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: ((thu sach) or (toc sach)) ky tang xa hoi. hieu ((ve cham) or (va cac)) duc va vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (toc sach)) ky tang xa hoi. hieu ((ve cham) OR (va cac)) duc va vanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (toc sach)) ky tang xa hoi. hieu ((ve cham) or (va cac)) duc va vanh dai cua tre*.