Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh tai, thanh oai
thanh van » thanh san, thanh toan, thanh phan
sang tao » hang tai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cua tre » cua te, cuu tre, cua triet

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 ky ((nang cao) or (sang tao)) roi. hieu ve pham duc va ((thanh vai) OR (thanh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang cao) OR (sang tao)) roi. hieu ve pham duc va ((thanh vai) OR (thanh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang cao) or (sang tao)) roi. hieu ve pham duc va ((thanh vai) OR (thanh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang cao) or (sang tao)) roi. hieu ve pham duc va ((thanh vai) OR (thanh van)) cua tre*.