Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
van cac » van hac, van cau, van bac
vu nang » vuc nang, va nang, vu dang
cua chu » sua chua
ma hoi » mai hoi, xa hoi, ma hoa
cua tu » cua tuc, cua su, cua cu

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