Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
va cao » va cac, va dao, va bao
vai va » mai va, dai va, hai va
x hoi » xa hoi, o hoi, x ho
va co » vo co
thiet » thieu

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 ty nang x hoi. lieu ((va cao) OR (va co)) xuc ((va thanh) or (van hanh)) vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang x hoi. lieu ((va cao) OR (va co)) xuc ((va thanh) OR (van hanh)) vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang x hoi. lieu ((va cao) OR (va co)) xuc ((va thanh) or (van hanh)) vai va thiet".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang x hoi. lieu ((va cao) OR (va co)) xuc ((va thanh) or (van hanh)) vai va thiet*.