Perhaps you should try some spelling variations:
chua thiet » chuan thiet, cua thiet, thua thiet
than luc » nhan luc, than duc, thanh luu
hieu van » thien van, lieu va, hieu ve
thu sach » tu sach, thuat sach, thuoc sach
lang xa » lang ha, dang xay, lang van
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang xa » nang x, nang ma, mang xa
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va chua » vua chua, ca chua, va chu
luc va » duc va, tuc va, loc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) than luc va hanh va chua thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (lang xa)) hoi. ((hieu van) OR (hieu va)) than luc va hanh va chua thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) than luc va hanh va chua thiet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) than luc va hanh va chua thiet*.