Perhaps you should try some spelling variations:
doan truc » doan trung, xuan truc, doan tu
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
dau truc » cau truc, dai truc, dau tu
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
sach v » sach va, sach y, sach 2
ma hoi » xa hoi, ma hoa, me hoi
v nang » va nang, vu nang, van nang
dai va » mai va

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 hoi) OR (mai hoi)). lieu va ((dau truc) OR (doan truc)) van hanh dai va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang ((ma hoi) or (mai hoi)). lieu va ((dau truc) OR (doan truc)) van hanh dai va triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((ma hoi) or (mai hoi)). lieu va ((dau truc) OR (doan truc)) van hanh dai va triet*.