Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
thu sach » tu sach, thuat sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, hoc sach
co sach » bo sach, cuon sach, hoc sach
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
va nham » va cham, va tham, va nha
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
dinh di » dinh du, dinh vi, danh di
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((so sach) or (co sach))) or (thu sach)) ky mang may hoi. lieu va nham thuc va dinh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((so sach) OR (co sach))) OR (thu sach)) ky mang may hoi. lieu va nham thuc va dinh di cua viet.
• Adding a wildcard symbol may retrieve word variants: ((((so sach) or (co sach))) or (thu sach)) ky mang may hoi. lieu va nham thuc va dinh di cua viet*.