Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
vi va » vi van, vai va, vu va

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