Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc va
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky nang ((ma hoi) or (mai hoi)). hieu ve cac toc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang ((ma hoi) OR (mai hoi)). hieu ve cac toc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang ((ma hoi) or (mai hoi)). hieu ve cac toc va hanh vi cua tre*.