Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
tai cua » thai cua, tai cuc, tri cua
cham lo » cham o, cham soc, cham hoi
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
y tang » 6 tang, 7 tang, 5 tang
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 ((y tang) or (ky tang)) mai hoi. hieu ve ((cham lo) or (cam lo)) ban thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((y tang) OR (ky tang)) mai hoi. hieu ve ((cham lo) OR (cam lo)) ban thanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((y tang) or (ky tang)) mai hoi. hieu ve ((cham lo) or (cam lo)) ban thanh tai cua tre*.