Perhaps you should try some spelling variations:
han dong » hanh dong, phan dong, han duong
chat luc » chat xuc, chat lua, nhan luc
sach han » sach tham, sach danh, sach nang
te sach » toc sach
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, ma hoa, me hoi
luc va » duc va, tuc va, loc va
dan va » dan ca, ban va, han va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach han dong ((ma hoi) OR (xa hoi)). hieu va chat luc va ((dan va) or (doan va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach han dong ((ma hoi) OR (xa hoi)). hieu va chat luc va ((dan va) OR (doan va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach han dong ((ma hoi) OR (xa hoi)). hieu va chat luc va ((dan va) or (doan va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach han dong ((ma hoi) OR (xa hoi)). hieu va chat luc va ((dan va) or (doan va)) cua tre*.