Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
va triet » va thiet, va trien, ve triet
tay lang » tai lang, tay tang, tay quang
thanh ve » hanh ve, thanh va, thanh vien
thanh vi » hanh vi, thanh va, nhanh vi
quan cau » quang cao, toan cau, quan ha
su sach » so sach, vu sach
ky dang » ky nang, ky danh
cau luc » cau truc, cau phuc
luc va » duc va, tuc va, loc va

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 sach ((tay lang) OR (ky dang)) xa hoi. hieu quan cau luc va ((thanh vi) OR (thanh ve)) va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((tay lang) or (ky dang)) xa hoi. hieu quan cau luc va ((thanh vi) OR (thanh ve)) va triet~".
• Adding a wildcard symbol may retrieve word variants: su sach ((tay lang) or (ky dang)) xa hoi. hieu quan cau luc va ((thanh vi) OR (thanh ve)) va triet*.