Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
kho tang » cao tang
hieu ve » hieu va, hieu van
duc ban » duc van, dua ban, duc man
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac

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)) ma hoi. hieu ve cac ((duc ban) OR (duc tan)) thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ((kho tang) OR (ky nang)) ma hoi. hieu ve cac ((duc ban) OR (duc tan)) thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ((kho tang) or (ky nang)) ma hoi. hieu ve cac ((duc ban) OR (duc tan)) thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ((kho tang) or (ky nang)) ma hoi. hieu ve cac ((duc ban) OR (duc tan)) thanh dai cua tre*.