Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh dai » hanh tai, hanh dao, vanh dai
va hanh » van hanh, va thanh, va danh
vu sach » vu bach, su sach, vu khach
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
hieu ve » hieu va, hieu van
cam tu » cam thu, nam tu, dam tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach y ((nang ma) or (tang ma)) hoi. hieu ve ((cam tu) or (am thuc)) va hanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((nang ma) OR (tang ma)) hoi. hieu ve ((cam tu) OR (am thuc)) va hanh dai cua viet.
• Adding a wildcard symbol may retrieve word variants: vu sach y ((nang ma) or (tang ma)) hoi. hieu ve ((cam tu) or (am thuc)) va hanh dai cua viet*.