Perhaps you should try some spelling variations:
thanh moi » thanh loi, thanh hoa, thanh hai
ban thanh » ban hanh, ban hang
quan tre » quan tren, quan tri, quang tri
moi quan » mai quan, hai quan, co quan
cau luc » cau truc, cau phuc
dau luc » dau luan, dau nuoc, dau luot
hieu va » lieu va, hieu qua
xac ky » sac ky, bac ky
x hoi » xa hoi, o hoi, x ho

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: su ((xac ky) OR (cac ky)) nang x hoi. hieu va ((dau luc) OR (cau luc)) ban thanh moi quan tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((xac ky) OR (cac ky)) nang x hoi. hieu va ((dau luc) or (cau luc)) ban thanh moi quan tre~".
• Adding a wildcard symbol may retrieve word variants: su ((xac ky) OR (cac ky)) nang x hoi. hieu va ((dau luc) or (cau luc)) ban thanh moi quan tre*.