Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
cao thu » cao thi, cac thu, ca thu
va danh » va dinh, va dan, va hanh
so viet » hoc viet
y nang » ky nang, ly nang, v nang
va cao » va cac, va co, va dao
ki so » khi so, ka so, 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 sach y nang x ho. hieu va cao thu ((va thanh) or (va danh)) ki so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y nang x ho. hieu va cao thu ((va thanh) OR (va danh)) ki so viet.
• Adding a wildcard symbol may retrieve word variants: vu sach y nang x ho. hieu va cao thu ((va thanh) or (va danh)) ki so viet*.