Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
bac dai » bach mai
mai hoi » mai khoi, dai hoi, lai hoi
va hanh » van hanh, va danh, ban hanh
va bac » van bac, va cac, va bai
y nang » ky nang, ly nang, v nang
ma hoi » xa hoi, ma hoa, me hoi
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((ma hoi) or (mai hoi)). lieu va bac dai ((va hanh) OR (va thanh)) di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((ma hoi) OR (mai hoi)). lieu va bac dai ((va hanh) OR (va thanh)) di cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((ma hoi) or (mai hoi)). lieu va bac dai ((va hanh) OR (va thanh)) di cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((ma hoi) or (mai hoi)). lieu va bac dai ((va hanh) OR (va thanh)) di cua vat*.