Perhaps you should try some spelling variations:
luoc van » luoc can, luoc va, luot van
doanh va » doan va, doanh tai, doanh cua
su sach » so sach, vu sach
co sach » bo sach, cuon sach, hoc sach
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
luc van » luu van, duc van, luc va
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (co sach)) ky dang xa hoi. lieu va cau ((luc van) OR (luoc van)) doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) ky dang xa hoi. lieu va cau ((luc van) OR (luoc van)) doanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) ky dang xa hoi. lieu va cau ((luc van) OR (luoc van)) doanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) ky dang xa hoi. lieu va cau ((luc van) OR (luoc van)) doanh va cua tre*.