Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
ky sang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
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: thu sach ky sang ((ma hoi) OR (mai hoi)). hieu van cam xuc ((ban hanh) or (van thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky sang ((ma hoi) OR (mai hoi)). hieu van cam xuc ((ban hanh) OR (van thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky sang ((ma hoi) OR (mai hoi)). hieu van cam xuc ((ban hanh) or (van thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky sang ((ma hoi) OR (mai hoi)). hieu van cam xuc ((ban hanh) or (van thanh)) vi cua tre*.