Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
va hanh » van hanh, va danh, ban hanh
cao duc » dao duc, cao suc, giao duc
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
ve cao » va cao, ve bao, ve cac
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: ((te sach) or (toc sach)) v nang ma hoi. hieu ve cao duc ((va hanh) or (va thanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) v nang ma hoi. hieu ve cao duc ((va hanh) OR (va thanh)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) v nang ma hoi. hieu ve cao duc ((va hanh) or (va thanh)) dai cua tre*.