Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh tai » thanh toan, doanh tai, thanh san
te sach » toc sach
cac tac » cac toc, cac bac, cac dac
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
tac va » tac da, tac xa, tuc va
ma hoi » mai hoi, ma hoa, me hoi
ve cac » va cac, vien cac

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 ky dang ((ma hoi) or (xa hoi)). hieu ve cac tac va ((thanh tai) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ((ma hoi) OR (xa hoi)). hieu ve cac tac va ((thanh tai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang ((ma hoi) or (xa hoi)). hieu ve cac tac va ((thanh tai) OR (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang ((ma hoi) or (xa hoi)). hieu ve cac tac va ((thanh tai) OR (thanh hai)) cua tre*.