Perhaps you should try some spelling variations:
manh thanh » danh thanh, minh thanh, manh thang
thanh hai » thanh phan, thanh hoa, thanh san
duc manh » suc manh, duc anh, duc minh
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
hai cua » thai cua, dai cua, hoi cua
su sach » so sach, vu sach
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va
su sac » su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) OR (su sach)) ky tang xa hoi. ((hieu ve) or (hieu van)) pham duc manh thanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky tang xa hoi. ((hieu ve) OR (hieu van)) pham duc manh thanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) OR (su sach)) ky tang xa hoi. ((hieu ve) or (hieu van)) pham duc manh thanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sac) OR (su sach)) ky tang xa hoi. ((hieu ve) or (hieu van)) pham duc manh thanh hai cua tre*.