Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
te sach » toc sach
sach ky » sac ky, sach y, sach ty
dong va » dong ha, luong va, dong hoa
hieu ve » hieu va, hieu van
cau luu » cau luc
luu van » cuu van, luan van, luu hanh
hanh tu » anh tu, danh tu
ve cau » ke cau, va cau, ve cac

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 ky ((dong va) or (dung va)) hoi. hieu ve cau luu van hanh tu va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((dong va) OR (dung va)) hoi. hieu ve cau luu van hanh tu va triet.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((dong va) or (dung va)) hoi. hieu ve cau luu van hanh tu va triet*.