Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh gia » danh gia, thanh gian, hinh giao
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
cac bac » cac bai, cac ban, cac cach
gia cua » gian cua, giau cua, gia cuc
cua tre » cua te, cuu tre, cua triet
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: tu sach ky nang ((x hoi) or (xa hoi)). hieu va ((cac duc) or (cac bac)) van hanh gia cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu va ((cac duc) OR (cac bac)) van hanh gia cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). hieu va ((cac duc) or (cac bac)) van hanh gia cua tre*.