Perhaps you should try some spelling variations:
doan truc » doan trung, xuan truc, doan tu
sua tiet » suat thiet, cua triet, cua thiet
danh dai » danh dau, danh di, danh sai
dau truc » cau truc, dai truc, dau tu
tang ma » mang may, tang van
va danh » va dinh, va dan, va hanh
nang xa » nang x, lang xa, nang ma
dai sua » dai cua
tu sach » thu sach, su sach, te sach

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 y ((nang xa) OR (tang ma)) hoi. lieu va ((dau truc) OR (doan truc)) va danh dai sua tiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (tang ma)) hoi. lieu va ((dau truc) OR (doan truc)) va danh dai sua tiet~".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (tang ma)) hoi. lieu va ((dau truc) OR (doan truc)) va danh dai sua tiet*.