Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tinh vai » tinh va, tinh hai, tinh bai
vai cua » dai cua, hai cua, lai cua
va tinh » may tinh
cham lo » cham o, cham soc, cham hoi
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 5 tang
cam lo » nam lo, cam ly, cam o
7 tang » 6 tang

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 (7 tang)) mai hoi. hieu ve ((cham lo) or (cam lo)) va tinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((y tang) OR (7 tang)) mai hoi. hieu ve ((cham lo) OR (cam lo)) va tinh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((y tang) or (7 tang)) mai hoi. hieu ve ((cham lo) or (cam lo)) va tinh vai cua tre*.