Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
su sach » vu sach
so sach » so sanh, bo sach, co sach
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
va hanh » van hanh, va thanh, va danh
luc va » duc va, tuc va, loc va
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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) OR (so sach)) ty xang xa hoi. hieu va cac luc va hanh tai ((cua tu) OR (cua su))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ty xang xa hoi. hieu va cac luc va hanh tai ((cua tu) OR (cua su))~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ty xang xa hoi. hieu va cac luc va hanh tai ((cua tu) OR (cua su))*.