Perhaps you should try some spelling variations:
dang hanh » dang thanh, ban hanh, dang van
cua viet » ca viet, hoa viet, cua vat
dan hanh » dan khanh, dan thanh, ban hanh
dang xay » dang van, van xay
ha thuc » va thuc, ha thuy, ha thu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va cua » va chua, via cua, ca cua
va ha » va hoa, va kha, va han

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 ky ((nang xa) or (dang xay)) hoi. lieu va ha thuc ((dan hanh) OR (dang hanh)) va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (dang xay)) hoi. lieu va ha thuc ((dan hanh) OR (dang hanh)) va cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (dang xay)) hoi. lieu va ha thuc ((dan hanh) OR (dang hanh)) va cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (dang xay)) hoi. lieu va ha thuc ((dan hanh) OR (dang hanh)) va cua viet*.