Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
xuc va » duc va, tuc va, luc 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 (thuoc sach)) ky sang ma hoi. ((hieu ve) or (hieu van)) cam xuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky sang ma hoi. ((hieu ve) OR (hieu van)) cam xuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky sang ma hoi. ((hieu ve) or (hieu van)) cam xuc va hanh vi cua tre*.