Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
kho tang » cao tang
hanh di » hanh vi, hanh de, hang di
luc van » luoc van, luu van, duc van
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
ky tang » ky nang, ky dang, ky trong
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu hoach) OR (tu sach)) ((ky tang) OR (kho tang)) xa hoi. hieu van cau luc van hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu hoach) or (tu sach)) ((ky tang) OR (kho tang)) xa hoi. hieu van cau luc van hanh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((thu hoach) or (tu sach)) ((ky tang) OR (kho tang)) xa hoi. hieu van cau luc van hanh di cua tre*.