Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
so sach » so sanh, bo sach, co sach
hai cuu » hai cua, hai chu, hai cuc
cam duc » cam xuc, cao duc, nam duoc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky tang ma hoi. hieu ve ((cam duc) or (pham duc)) ((van thanh) or (van ban)) hai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky tang ma hoi. hieu ve ((cam duc) OR (pham duc)) ((van thanh) OR (van ban)) hai cuu tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky tang ma hoi. hieu ve ((cam duc) or (pham duc)) ((van thanh) or (van ban)) hai cuu tre*.