Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
duc van » duc va, duc tan, duc manh
va chat » van chat, va phat, cao chat
va cham » va tham
sach ly » sach y, sach lo, sach ty
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
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: te sach ly nang ((mai hoi) or (dai hoi)). hieu ((va cham) or (va chat)) duc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang ((mai hoi) OR (dai hoi)). hieu ((va cham) OR (va chat)) duc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ly nang ((mai hoi) or (dai hoi)). hieu ((va cham) or (va chat)) duc van hanh vi cua tre*.