Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
cham hoi » cham voi, cham h'roi, pham hoai
hanh tai » thanh tai, hang tai, han tai
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ty tang » tay tang, ty xang, ty hang
cam lo » nam lo, cam ly, cam o
ma hoi » mai hoi, xa hoi, ma hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ty tang ma hoi. hieu ve ((cham hoi) OR (cam lo)) va ((hanh vi) OR (hanh tai)) cua tre~.
• Adding a wildcard symbol may retrieve word variants: thuat sach ty tang ma hoi. hieu ve ((cham hoi) or (cam lo)) va ((hanh vi) or (hanh tai)) cua tre*.