Perhaps you should try some spelling variations:
hanh sinh » hanh tinh, hanh dinh, hinh sinh
sinh cua » manh cua, dinh cuu, sinh va
dang xay » dang van, van xay
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
ve bao » te bao, va bao
ve co » va co, de co, ke co

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 dang xay hoi. hieu ((((ve co) or (vo co))) or (ve bao)) duc van hanh sinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xay hoi. hieu ((((ve co) OR (vo co))) OR (ve bao)) duc van hanh sinh cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xay hoi. hieu ((((ve co) or (vo co))) or (ve bao)) duc van hanh sinh cua tre*.