Perhaps you should try some spelling variations:
ban hanh » ban hang
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
ve bac » ve bao, ve cac, ve ban
bo ban » co ban, lo ban, do ban
di cua » dai cua, doi cua, de cua
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 sach ky nang ((x hoi) or (xa hoi)). hieu ve bac bo ban hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x hoi) OR (xa hoi)). hieu ve bac bo ban hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x hoi) or (xa hoi)). hieu ve bac bo ban hanh di cua tre*.