Perhaps you should try some spelling variations:
va tuyen » va truyen, tac tuyen, ke tuyen
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac

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 y ((nang xa) or (nang x)) hoi. hieu ve cac duc va hanh vai ((va triet) or (va tuyen))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (nang x)) hoi. hieu ve cac duc va hanh vai ((va triet) OR (va tuyen)).
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (nang x)) hoi. hieu ve cac duc va hanh vai ((va triet) or (va tuyen))*.