Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
cac chuc » cac chu, cac chung, canh chuc
hanh dai » hanh tai, hanh dao, vanh dai
co sach » bo sach, cuon sach, hoc sach
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
tai hoa » tai khoa, thai hoa, thi hoa
yu hang » yu zhang, yu pang, yu wang
y hang » ly hang, ty hang, _ hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ((y hang) or (yu hang)) tai hoa. hieu ve ((cac chuc) OR (cach thuc)) va hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((y hang) OR (yu hang)) tai hoa. hieu ve ((cac chuc) OR (cach thuc)) va hanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((y hang) or (yu hang)) tai hoa. hieu ve ((cac chuc) OR (cach thuc)) va hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: co sach ((y hang) or (yu hang)) tai hoa. hieu ve ((cac chuc) OR (cach thuc)) va hanh dai cua tre*.