Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
hieu van » hieu va, thien van, lieu va
thu sach » tu sach, thuat sach, thuoc sach
lang xa » lang ha, dang xay, lang van
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
nang xa » nang x, nang ma, mang xa
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
van cau » van dau, van hau, van chat

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 cau thuc va hanh ((vai cua) OR (hai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (lang xa)) hoi. hieu van cau thuc va hanh ((vai cua) OR (hai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (lang xa)) hoi. hieu van cau thuc va hanh ((vai cua) OR (hai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang xa)) hoi. hieu van cau thuc va hanh ((vai cua) OR (hai cua)) triet*.