Perhaps you should try some spelling variations:
thanh day » thanh dat, thanh tay, thanh dam
ban thanh » ban hanh, ban hang
hieu ve » hieu va, hieu van
day cua » dai cua
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
ky tang » ky nang, ky dang, kho tang
sac ky » cac ky, sai ky
ve cam » ve cham, ve cac, va cam
ma hoi » xa hoi, ma hoa, me hoi
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 ky tang ((ma hoi) or (mai hoi)). hieu ve cam duc ban thanh day cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky tang ((ma hoi) OR (mai hoi)). hieu ve cam duc ban thanh day cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky tang ((ma hoi) or (mai hoi)). hieu ve cam duc ban thanh day cua tre*.