Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
cham cua » chat cua, cham cuu, ham cua
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
va cham » va chat, va tham
cua tre » cua te, cuu tre, cua triet
va hoi » xa hoi, va hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty hang va hoi. hieu va cham cua ban ((thanh dai) or (doanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty hang va hoi. hieu va cham cua ban ((thanh dai) OR (doanh tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty hang va hoi. hieu va cham cua ban ((thanh dai) or (doanh tai)) cua tre*.