Perhaps you should try some spelling variations:
danh vai » danh sai, danh va, doanh van
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
cau luc » cau truc, cau phuc
so sach » so sanh, co sach, hoc sach
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet
_ dang » _ dan, 2 dang, _ danh
va cau » van cau, va cac, va dau
luc va » duc va, tuc va, loc va
y dang » ky dang, 2 dang, b dang

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

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