Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham thuc » nham thuc, pham thuc, tham thuc
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
co sach » bo sach, cuon sach, hoc sach
ky cong » ke cong, ly cong, khu cong
cong ha » cong hoa, dong ha, cong tac
hieu va » lieu va, hieu qua
va cham » va chat, va tham
hanh de » hanh ve, hanh kem
de cua » le cua, te cua, dieu cua

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) or (co sach)) ky cong ha noi. hieu va cham thuc van hanh de cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (co sach)) ky cong ha noi. hieu va cham thuc van hanh de cua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (co sach)) ky cong ha noi. hieu va cham thuc van hanh de cua triet*.