Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
giau cua » gian cua, gia cua, dieu cua
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
via cua » gia cua, gian cua, rija cua
y nang » ky nang, ly nang, v nang
va tai » va tac, va tap
tai so » tai sao, dai so, tai co
so vat » so van

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang cao hoi. hieu va tai so vat hanh ((via cua) OR (giau cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang cao hoi. hieu va tai so vat hanh ((via cua) OR (giau cua)) te".
• Adding a wildcard symbol may retrieve word variants: su sach y nang cao hoi. hieu va tai so vat hanh ((via cua) OR (giau cua)) te*.