Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
tu sach » thu sach, su sach, te sach
tay hoi » tay ho, tao hoi, tay thai
xay hoi » xa hoi, cay phoi, gay thoi
cua tre » cua te, cuu tre, cua triet
sach 2 » sach y
loc va » hoc va, luc va
2 dang » 2 danh, _ dang, b dang
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach 2 dang ((xay hoi) OR (tay hoi)). hieu va chat ((loc va) or (duc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach 2 dang ((xay hoi) OR (tay hoi)). hieu va chat ((loc va) OR (duc va)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach 2 dang ((xay hoi) OR (tay hoi)). hieu va chat ((loc va) or (duc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach 2 dang ((xay hoi) OR (tay hoi)). hieu va chat ((loc va) or (duc va)) hanh vi cua tre*.