Perhaps you should try some spelling variations:
va triet » va trien, ve triet, cua triet
hanh vai » hanh vi, hanh va, hanh tai
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
bo sach » co sach, hoc sach
hieu ve » hieu va, hieu van
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
ve am » va am
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach y ((nang ma) or (sang ma)) hoi. hieu ve am thuc dan hanh vai ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach y ((nang ma) OR (sang ma)) hoi. hieu ve am thuc dan hanh vai ((va triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: bo sach y ((nang ma) or (sang ma)) hoi. hieu ve am thuc dan hanh vai ((va triet) or (va thiet))*.