Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, thien van, lieu va
nam duoc » nam thuoc, da duoc, dat duoc
va thanh » gia thanh, ban thanh, va tinh
nam xua » nam cua, nam mua, nam qua
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
x hoi » o hoi, x ho, 5 hoi

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 nang ((x hoi) or (xa hoi)). hieu van ((nam duoc) or (nam xua)) va thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((x hoi) OR (xa hoi)). hieu van ((nam duoc) OR (nam xua)) va thanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((x hoi) or (xa hoi)). hieu van ((nam duoc) or (nam xua)) va thanh vai cua tre*.