Perhaps you should try some spelling variations:
hanh sinh » hanh tinh, hanh dinh, hinh sinh
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
sinh cua » manh cua, dinh cuu, sinh va
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
van hac » van hoc, van ha, van hai
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky dang xay hoi. hieu van hac ((xuc va) or (thuc vat)) hanh sinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang xay hoi. hieu van hac ((xuc va) OR (thuc vat)) hanh sinh cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky dang xay hoi. hieu van hac ((xuc va) or (thuc vat)) hanh sinh cua tre*.