Perhaps you should try some spelling variations:
thieu bien » thieu nien, tieu bieu, hien bien
cua viet » ca viet, hoa viet, cua vat
van hanh » van thanh, ban hanh, van anh
cap nuoc » dat nuoc
sach ky » sac ky, sach y, sach ty
cac luc » cau luc, coc luc, cac nuoc
lang xa » lang ha, dang xay, lang van
hanh va » hang va, hanh vi
tu sach » thu sach, su sach, te sach
va cua » va chua, via cua, ca cua

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 ((lang xa) or (nang x)) hoi. thieu bien ((cac luc) or (cap nuoc)) van hanh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((lang xa) OR (nang x)) hoi. thieu bien ((cac luc) OR (cap nuoc)) van hanh va cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((lang xa) or (nang x)) hoi. thieu bien ((cac luc) or (cap nuoc)) van hanh va cua viet*.