Perhaps you should try some spelling variations:
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
dia danh » dia ban, gia dinh
va thanh » gia thanh, ban thanh, va tinh
vu sach » vu bach, su sach, vu khach
su viet » so viet
sach ky » sac ky, sach y, sach ty
cam thu » nam thu, cac thu, ca thu
van cam » van nam, van lam, van cau
ve su » va 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 sach ky nang x ho. hieu van cam thu ((((ban hanh) or (va thanh))) or (dia danh)) ve su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x ho. hieu van cam thu ((((ban hanh) OR (va thanh))) OR (dia danh)) ve su viet.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x ho. hieu van cam thu ((((ban hanh) or (va thanh))) or (dia danh)) ve su viet*.