Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
thanh dai » thanh hai, thanh tai, thanh oai
kho tang » cao tang
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
su sac » su sach, su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ((kho tang) or (ky nang)) xa hoi. hieu ve cac duc ban ((thanh dai) or (thanh dat)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ((kho tang) OR (ky nang)) xa hoi. hieu ve cac duc ban ((thanh dai) OR (thanh dat)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ((kho tang) or (ky nang)) xa hoi. hieu ve cac duc ban ((thanh dai) or (thanh dat)) cua tre*.