Perhaps you should try some spelling variations:
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
bach ky » bac ky
va danh » va dinh, va dan, va hanh
su viet » so viet
cam tu » cam thu, nam tu, tam tu
dam tu » nam tu, tam tu, dam thuc
x hoi » xa hoi, o hoi, x ho
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ky nang x hoi. hieu van ((cam tu) OR (dam tu)) ((ban hanh) or (va danh)) vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ky nang x hoi. hieu van ((cam tu) OR (dam tu)) ((ban hanh) OR (va danh)) vi su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ky nang x hoi. hieu van ((cam tu) OR (dam tu)) ((ban hanh) or (va danh)) vi su viet".
• Adding a wildcard symbol may retrieve word variants: vu bach ky nang x hoi. hieu van ((cam tu) OR (dam tu)) ((ban hanh) or (va danh)) vi su viet*.