Perhaps you should try some spelling variations:
chua thiet » chuan thiet, cua thiet, thua thiet
hieu van » hieu va, thien van, lieu va
thu sach » tu sach, thuat sach, thuoc sach
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
van hac » van hoc, van ha, van hai
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
va chua » vua chua, ca chua, va chu
hac luc » nhan luc, than luc

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 hac luc ((va hanh) OR (va danh)) 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 hac luc ((va hanh) OR (va danh)) 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 hac luc ((va hanh) OR (va danh)) va chua thiet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang xa)) hoi. hieu van hac luc ((va hanh) OR (va danh)) va chua thiet*.