Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tang van » dang van, hoang van, trong van
hanh di » hanh vi, hanh de, hang di
tac van » tac vang, cac van, tac va
cac tac » cac toc, cac bac, cac dac
hieu ve » hieu va, hieu van
sach ky » sac ky, sach ty, sach kem
van hoi » van hoa, van hoc, van hoe
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) OR (sach y)) tang van hoi. ((hieu ve) or (lieu va)) cac tac van hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) tang van hoi. ((hieu ve) OR (lieu va)) cac tac van hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sach y)) tang van hoi. ((hieu ve) or (lieu va)) cac tac van hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sach y)) tang van hoi. ((hieu ve) or (lieu va)) cac tac van hanh di cua tre*.