Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh oai
thanh dat » thanh san, thanh hai, thanh van
su sach » so sach, vu sach
sach ke » sach kem, sach de, sach che
ke mang » ke nang, ke trang
may thi » may thoi, day thi, mai thi
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam

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 ke mang may thi. hieu ve cam duc ban ((thanh dai) or (thanh dat)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ke mang may thi. hieu ve cam duc ban ((thanh dai) OR (thanh dat)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ke mang may thi. hieu ve cam duc ban ((thanh dai) or (thanh dat)) cua tre*.