Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cham thuc » nham thuc, pham thuc, tham thuc
thu sach » tu sach, thuat sach, thu hoach
cua viet » ca viet, hoa viet, cua vat
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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) OR (thuoc sach))) or (co sach)) ky nang x hoi. hieu ve cham thuc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((thu sach) OR (thuoc sach))) OR (co sach)) ky nang x hoi. hieu ve cham thuc va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((thu sach) OR (thuoc sach))) or (co sach)) ky nang x hoi. hieu ve cham thuc va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((((thu sach) OR (thuoc sach))) or (co sach)) ky nang x hoi. hieu ve cham thuc va hanh vi cua viet*.