Perhaps you should try some spelling variations:
sieu viet » su viet, dien viet, bien viet
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
hanh va » hang va, hanh vi
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
nang xa » lang xa, nang ma, mang xa
lam so » lam son, nam so, ham so
va cuu » va cau, va chu, va huu
lam vo » lam co, lam vu

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 (nang x)) hoi. sieu viet ((lam vo) OR (lam so)) van hanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang x)) hoi. sieu viet ((lam vo) OR (lam so)) van hanh va cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang x)) hoi. sieu viet ((lam vo) OR (lam so)) van hanh va cuu tre*".