Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cham thuc » nham thuc, pham thuc, tham thuc
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
va triet » va thiet, va trien, ve triet
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) or (tu sach)) ky ((nang xa) or (lang xa)) hoi. hieu van cham thuc va danh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (tu sach)) ky ((nang xa) OR (lang xa)) hoi. hieu van cham thuc va danh vi va triet.
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (tu sach)) ky ((nang xa) or (lang xa)) hoi. hieu van cham thuc va danh vi va triet*.