Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sach va » sach xa, sach ha, sach dao
sach v » sach y, sach 2, sach vay
vi cua » vai cua, di cua
cua su » qua su

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 v) or (sach va)) ((nang ma) or (tang ma)) hoi. hieu van cac luc van hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach v) OR (sach va)) ((nang ma) OR (tang ma)) hoi. hieu van cac luc van hanh vi cua su.
• Adding a wildcard symbol may retrieve word variants: te ((sach v) or (sach va)) ((nang ma) or (tang ma)) hoi. hieu van cac luc van hanh vi cua su*.