Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau thuc » cau truc, cuu thuc, can thuc
hanh tai » thanh tai, hang tai, han tai
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
va cau » van cau, va cac, va dau
tai va » thai va, mai va, tri 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 va cau thuc va hanh tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (lang xa)) hoi. hieu va cau thuc va hanh tai va triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (lang xa)) hoi. hieu va cau thuc va hanh tai va triet*.