Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
cac dat » cac dan, cai dat, cac dai
va hanh » va thanh, va danh, ban hanh
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang ((ma hoa) OR (mai hoi)). lieu va cac dat ((va hanh) OR (van hanh)) vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang ((ma hoa) or (mai hoi)). lieu va cac dat ((va hanh) OR (van hanh)) vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((ma hoa) or (mai hoi)). lieu va cac dat ((va hanh) OR (van hanh)) vi cua vat*.