Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
mai hoi » mai khoi, dai hoi, lai hoi
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
cam lo » nam lo, cam ly, cam o

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 tang ((ma hoi) OR (mai hoi)). hieu van ((cham h'roi) or (cam lo)) gia thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky tang ((ma hoi) OR (mai hoi)). hieu van ((cham h'roi) OR (cam lo)) gia thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky tang ((ma hoi) OR (mai hoi)). hieu van ((cham h'roi) or (cam lo)) gia thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky tang ((ma hoi) OR (mai hoi)). hieu van ((cham h'roi) or (cam lo)) gia thanh vai cua tre*.