Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
duy sang » duy van, duy can, duy anh
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ty sang » ty xang, ty hang, thu sang
ve cac » va cac, vien cac
me hoi » le hoi

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 ((ty sang) or (duy sang)) ((me hoi) or (xa hoi)). hieu ve cac duc van hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty sang) OR (duy sang)) ((me hoi) OR (xa hoi)). hieu ve cac duc van hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty sang) or (duy sang)) ((me hoi) or (xa hoi)). hieu ve cac duc van hanh tai cua tre*.