Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
ky dang » ky danh
hieu le » hieu ve, hieu he, hieu ly
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh vu » hanh vi, hanh va, hanh tu
ha hoi » hoa hoi, ha noi, xa hoi
le nam » ly nam, he nam, le na
vu va » vu van, tu va, su va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky dang) or (ky nang)) ha hoi. hieu le nam thuc va hanh vu va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky nang)) ha hoi. hieu le nam thuc va hanh vu va triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky nang)) ha hoi. hieu le nam thuc va hanh vu va triet*.