Perhaps you should try some spelling variations:
manh dung » manh hung, manh tung, anh dung
cach thoi » cac thoi, cach thuc, cach noi
duc manh » suc manh, duc anh, duc minh
chat duc » chat xuc, chat doc, chet duoc
mai khoi » mai khoa, tai khoa, cac khoi
tai cua » thai cua, tai cuc, tri cua
ve chat » va chat, van chat
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
sac ky » cac ky, sai ky

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 ky) or (sac ky)) lang ((mai khoi) or (cach thoi)). hieu ve chat duc manh dung tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) lang ((mai khoi) OR (cach thoi)). hieu ve chat duc manh dung tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) lang ((mai khoi) or (cach thoi)). hieu ve chat duc manh dung tai cua tre*.